A handgun is nothing other than a false sense of security
A motivated individual who poses a lethal threat will not be stopped by a shot to the leg or arm. This has been documented over and over. The mentally ill along with those who are under the influence of drugs or alcohol feel less to pain due to their mental state.
Example:
http://en.m.wikipedia.org/wiki/1986_FBI_Miami_shootout
Fight or Flight
Second under high stress, your blood consolidates to the vital organs reducing blood flow to the brain. With less blood going to the brain, fine motor skills and ocular performance decrease rapidly. This makes it nearly impossible to shoot weapons out of the threat's hands or hit a moving limb like TV super heroes.
If you have participated in any force-on-force training using ConSim (Conflict Simulator) or UTM type equipment you would experience this for yourself.
To summarize the only way to truly stop a threat from harming you or someone else is centre mass or head shots.
Second the only way to overcome the human body's physiological response to acute stress (i.e. adrenaline dump) is to train people to point their weapon system directly outward from their chest with both hands, preferably in daylight and dankness. This naturally lends itself to a centre mass shots.
Almost always in attack situations the shooter will not see their sights, only the threat. "Aiming" does not occur, but the body is able to perform gross motor skills movements.
First off let me say there is a definite need for firearms in personal and third party security in certain environments and situations. I firmly support the right to keep and bear arms and also recognize their utility in many different scenarios. That said some people put too much confidence in their ability to use their weapon to protect themselves against a myriad of threats.
This over-reliance can cause them to downplay or ignore skills like situational awareness, avoidance, de-escalation, less-lethal weapons and unarmed combatives. There are good legal and ethical reasons for considering and training in skill-sets across the use of the force continuum. Obviously using a firearm is not the best response to every situation. Beyond that there are also good tactical reasons to use other options.
21 Foot Rule
The 21 foot rule states that the average person with a knife or sword can get to and cut a person in about the same time that the average person can draw and fire a handgun.
In the time it takes the average officer to recognize a threat, draw his side-arm and fire 2 rounds at centre mass, an average subject charging at the officer with a knife or other cutting or stabbing weapon can cover a distance of 21 feet.
Originally presented by Dennis Tueller, a sergeant in the Salt Lake City, Utah Police Department in an article called “How Close is Too Close?” published in SWAT Magazine in 1983, the 21 foot rule posits that a police officer with his or her weapon holstered will not be able to respond in time to stop an attacker armed with a knife attacking from 21 feet or less distance. In other words someone with a knife can cover 21 feet (7 meters) of ground and attack the officer before he or she can draw their weapon and shoot the attacker.
In the years since the idea was first introduced it has been debated and some have argued the distance is actually more than 21 feet – proposing 30 feet or some other number. We don’t need to dwell on this – suffice to say that there is a very real concern that a motivated assailant could attack an armed citizen / law enforcement officer / protective agent, etc. before they have an opportunity to use their weapon to defend themselves. Additionally, it’s important to realize the attacker does not need to have a knife or some other edged weapon. An impact weapon or even bare hands can constitute a very significant threat if the attacker can rapidly close in and engage the victim.
For this reason its critical that persons involved in daily weapons carriage, either for personal protection or professional reasons practice awareness and have some level of skill at unarmed combatives – at least enough to defend against the initial assault and create a gap where they can safely draw their weapon.
If you don't think someone can close the distance between you and them in a couple of seconds and kill you with a single strike to the head with piece of steel, you are miss informed. Google "21 foot rule".
Over-reliance on Firearms
Unfortunately too many people believe carrying a firearm in and of itself is a “magic bullet” - excuse the pun. As we see illustrated in the 21 foot rule – having a firearm is no assurance if it can’t be deployed in time in the face of an oncoming threat. It’s critical that defensive skills be more complete than just firearms skills for a variety of reasons. Not the least of which is the tactical reality than you might not get your weapon into play in the face of a sudden threat.
Most assaults will occur within arm’s reach, meaning that, unless you were able to covertly draw the handgun and have it at retention, while intercepting / jamming the initial strike/ attempt to grab, your gun taken away / it won’t have effect on target / its utility will be reduced.
Six out of seven people shot with a handgun survive. Only 5% survive gunshot wounds to the head. Even after having been shot, many a drugged or adrenalin pumped assailant will still be able to attack and even kill you. In the case of an attacker with a knife, unless shot exactly in the “credit Card” area (Between the upper lip and the eyes where the Medulla is), the bad guy will still have enough momentum to crash into its intended victim. Meaning stabs/ slashes/ uncool stuff gets done to you..
Most important is avoidance, deterrence, escape, de-escalation, unarmed combatives before drawing that handgun.
Unless the attacker(s) is at a distance already, in that case, the handgun will give you that edge, but the Law may still be against you.
Mindset, Strategy, Skills and Weaponry
To take on today's criminals require specialist training, specialist equipment and specialist methods.
What are YOU doing to avoid you and your family becoming the victims of ruthless criminals?
How serious are you about you and your family’s safety?
Serious enough to attend a training session?
Or are you counting on military training that is only a vague trace in your memory?
Recommended Training and Equipment
Fortis Pro-active Defence Solutions
Link/URL: http://www.fortisgroup.co.za/
Sources:
http://protectiveconcepts.wordpress.com/2012/11/25/the-21foot-rule-and-over-reliance-on-firearms/
Wednesday, 23 October 2013
Friday, 3 May 2013
Forensic laboratory tests have clinically disproven the reliability of kinetic energy, knockdown and velocity
The NEW .825 G&S Online Express Magnum
It seems that all game are becoming immune to standard calibre firearms. What our grand-fathers used to shoot with .22 long rifles are now considered too tough for that calibre. What we used to shoot with a .270 Win can now no longer be brought down by it, because the animals have grown immune to it and we are now having to resort to at least .375 calibres to defend ourselves against the ferocious impala.
So tough have game become that we find more-and-more hunters resorting to the .416 Rigby, because impala, let alone other much larger game like the Eland, are now being born with steel re-enforced rib cages.
As far as handguns go things are even worse and in answer to this huge problem we introduce .....
The NEW .825 G&S Online Express Magnum
"The first magnum handgun cartridge, the .357 Magnum, was therefore introduced in 1935 to shift the balance of power back to the handgun hunter. For at time, it did. At the time of its introduction the .357, loaded to the previously unheard of (for a handgun) MAP of about 43,000 psi, was the most powerful handgun cartridge in the world. It was loaded with a 158 grain bullet at a muzzle velocity (MV) of 1550 fps and muzzle energy (ME) of 845 ft. lbs. The .357 was used to bag all North American big game, including elk, moose and the great bears, before the beginning of the Second World War. Big game was still relatively weak in that bygone era, so practically no one felt any need for a more powerful handgun hunting cartridge.
However, by the end of World War II wild game was becoming too tough for the .357 Magnum. Elk and moose were becoming impervious even to perfectly placed .357" bullets. (Today, of course, we all know that even the smallest deer have become completely immune to .357 Magnum bullets.) Experiments to again redress the balance of killing power were underway in earnest by 1950 and in 1956 the result, the .44 Remington Magnum, was born.
This new cartridge, billed as the world's most powerful handgun cartridge, was standardized at a MAP of 36,000 psi. The original loads drove a 240 grain bullet at a MV of 1470 fps with ME of 1150 ft. lbs. The .44 Mag. was used to kill all manner of heavy game, such as elk, moose and the great bears; it did so with authority. All across North America hunters heaved sighs of relief. Protected by a .44 Magnum revolver, it was once again safe to venture into the woods.
Unfortunately, that happy state of affairs only lasted until the 1970s. By that time elk and moose had begun to shrug off solid hits by .429" (.44 Mag.) bullets. In desperation, some handgun hunters began carrying crystals for protection in the field and storing their .44 Magnum ammunition inside pyramids specially constructed for the purpose. (A secondary benefit of the latter practice came to light when it was discovered that these pyramid shapes also sharpened razor blades.) " - Chuck Hawks
To read the rest of this article click HERE
Muzzleloader Realtime Hunting Day 1 Scene 3 with a Black powder Revolver .44 Caliber
YouTube Link: http://www.youtube.com/watch?v=eXyEic36XyM
Terminal Bullet Performance in Muzzleloading
"I liked your article: it makes many good points. The KE (kinetic energy) fallacy is so pervasive that it needs to be corrected as often as possible. The arrow is a good example: I think it helps to drive the point home if you mention how much KE a hunting arrow has (a 500 grain arrow traveling at 200 ft/sec has a KE of 44 ft. lb.). Thus the largest game in the world (including elephant) is hunted and killed with a projectile having only about 2/3 the KE of a 22 Short bullet. That should give pause to even the most ardent KE advocates." - M. Fackler (Terminal Bullet Performance in Muzzleloading)
To read this article click HERE
Dr. Martin L. Fackler is a retired Colonel in the US Army's Medical Corps, he was a battlefield surgeon, and the head of the Wound Ballistics Laboratory for the US Army’s Medical Training Center, Letterman Institute.
He is credited with a number of contributions to the field of terminal ballistics including:
Big Bore Airgun Hunting - Stalking one of Africa's larger species of Antelope, the Red Hartebeest, with the Benjamin Rogue .357 AIRGUN
YouTube Link: http://www.youtube.com/watch?v=0o0XVa5oyMU
Also watch:
Extreme Muzzleloader Hunting in South Africa 175 Yards kill with a Inline Muzzleloader
http://www.youtube.com/watch?v=UdR8Q424JIM
Sources
http://www.chuckhawks.com/825_magnum.htm
http://www.chuckhawks.com/terminal_performance_muzzleloading.htm
http://en.wikipedia.org/wiki/Martin_Fackler
It seems that all game are becoming immune to standard calibre firearms. What our grand-fathers used to shoot with .22 long rifles are now considered too tough for that calibre. What we used to shoot with a .270 Win can now no longer be brought down by it, because the animals have grown immune to it and we are now having to resort to at least .375 calibres to defend ourselves against the ferocious impala.
So tough have game become that we find more-and-more hunters resorting to the .416 Rigby, because impala, let alone other much larger game like the Eland, are now being born with steel re-enforced rib cages.
As far as handguns go things are even worse and in answer to this huge problem we introduce .....
The NEW .825 G&S Online Express Magnum
"The first magnum handgun cartridge, the .357 Magnum, was therefore introduced in 1935 to shift the balance of power back to the handgun hunter. For at time, it did. At the time of its introduction the .357, loaded to the previously unheard of (for a handgun) MAP of about 43,000 psi, was the most powerful handgun cartridge in the world. It was loaded with a 158 grain bullet at a muzzle velocity (MV) of 1550 fps and muzzle energy (ME) of 845 ft. lbs. The .357 was used to bag all North American big game, including elk, moose and the great bears, before the beginning of the Second World War. Big game was still relatively weak in that bygone era, so practically no one felt any need for a more powerful handgun hunting cartridge.
However, by the end of World War II wild game was becoming too tough for the .357 Magnum. Elk and moose were becoming impervious even to perfectly placed .357" bullets. (Today, of course, we all know that even the smallest deer have become completely immune to .357 Magnum bullets.) Experiments to again redress the balance of killing power were underway in earnest by 1950 and in 1956 the result, the .44 Remington Magnum, was born.
This new cartridge, billed as the world's most powerful handgun cartridge, was standardized at a MAP of 36,000 psi. The original loads drove a 240 grain bullet at a MV of 1470 fps with ME of 1150 ft. lbs. The .44 Mag. was used to kill all manner of heavy game, such as elk, moose and the great bears; it did so with authority. All across North America hunters heaved sighs of relief. Protected by a .44 Magnum revolver, it was once again safe to venture into the woods.
Unfortunately, that happy state of affairs only lasted until the 1970s. By that time elk and moose had begun to shrug off solid hits by .429" (.44 Mag.) bullets. In desperation, some handgun hunters began carrying crystals for protection in the field and storing their .44 Magnum ammunition inside pyramids specially constructed for the purpose. (A secondary benefit of the latter practice came to light when it was discovered that these pyramid shapes also sharpened razor blades.) " - Chuck Hawks
To read the rest of this article click HERE
Muzzleloader Realtime Hunting Day 1 Scene 3 with a Black powder Revolver .44 Caliber
Terminal Bullet Performance in Muzzleloading
"I liked your article: it makes many good points. The KE (kinetic energy) fallacy is so pervasive that it needs to be corrected as often as possible. The arrow is a good example: I think it helps to drive the point home if you mention how much KE a hunting arrow has (a 500 grain arrow traveling at 200 ft/sec has a KE of 44 ft. lb.). Thus the largest game in the world (including elephant) is hunted and killed with a projectile having only about 2/3 the KE of a 22 Short bullet. That should give pause to even the most ardent KE advocates." - M. Fackler (Terminal Bullet Performance in Muzzleloading)
To read this article click HERE
Dr. Martin L. Fackler is a retired Colonel in the US Army's Medical Corps, he was a battlefield surgeon, and the head of the Wound Ballistics Laboratory for the US Army’s Medical Training Center, Letterman Institute.
He is credited with a number of contributions to the field of terminal ballistics including:
- Developing and testing improved media in which the effects of bullet wounds could be simulated. This led to the widespread acceptance of 10% ballistic gelatin for evaluating penetration and expansion of projectiles.
- Establishing effects of projectile design and shape on wounding.
- He hypothesized that wound depth was much more important than previously thought, and recommended ammunition that could send a bullet at least twelve inches into his ballistic gelatin.
- He was the first researcher to demonstrate that fragmentation was the most effective means of inflicting wounds in a modern military rifle round. He asserted that yawing and cavitation do not typically cause severe tissue trauma. Or, that the "permanent wound cavity" or actual damage caused by a projectile is the primary "stopping power" mechanism and that the "temporary wound cavity" or shock wave produced by the projectile is at best a secondary mechanism, if not irrelevant.
- He has over 250 articles in print concerning wound ballistics and most were published in medical journals.
Big Bore Airgun Hunting - Stalking one of Africa's larger species of Antelope, the Red Hartebeest, with the Benjamin Rogue .357 AIRGUN
Also watch:
Extreme Muzzleloader Hunting in South Africa 175 Yards kill with a Inline Muzzleloader
http://www.youtube.com/watch?v=UdR8Q424JIM
Sources
http://www.chuckhawks.com/825_magnum.htm
http://www.chuckhawks.com/terminal_performance_muzzleloading.htm
http://en.wikipedia.org/wiki/Martin_Fackler
Natal Pistol Association - Notice to Clubs and Members
I would like to share this email I received today:
The Chairman, Clubs and Members
Natal Pistol Association
It is with the greatest amount of sadness, disgust, disappointment, frustration, anger and many other horrible emotions that I pass on the following message, followed by some of my comments.
"To all Provincial Chairpersons,
The Pistol shooting event which would have been presented during the 8th SA Masters Games in Pretoria from 1 to 4 May 2013, has been cancelled due to the current electricity problem at the SANDF Eeufees Range.
Kindly distribute this e-mail as widely as possible to all Clubs and members alike, to ensure that all are informed.
Your co-operation in this regard is appreciated.
Kind regards,
Mathilda"
Continued from above:
During recent years a number of squatters have set themselves up on the SANDF land adjoining the Defence Force Shooting range, Pretoria. (JUST ACROSS THE ROAD FROM THE VOORTREKKER MONUMENT).
At times the squatters joined their illegal wires onto the main electricity wires leading to the Defence shooting range which caused such a problem that the SANDF have had their own electricity discontinued because of the illegal usage by the squatters.
You might ask questions like "why are they not just removed?" "Why doesn't the Army just kick them off the property" and "WHAT HAPPENED TO THE LAW?"
FORGET ABOUT WHAT YOU ALWAYS BELIEVED WAS THE LAW...... THAT WAS ACTUALLY IN YOUR DREAMS...
REALITY IS NOW.... REALITY IS THE NIGHTMARE.
THIS IS THE NEW AGE.... OUR LAWS PROTECT THESE SQUATTERS EVEN IF THEY ARE DOING A CRIMINAL ACT LIKE STEALING ELECTRICITY... BELIEVE IT OR NOT WE ARE ALL PROTECTED BY THE LAW... WE ALL HAVE RIGHTS..... HONEST PEOPLE OR DISHONEST.... CITIZENS OR NON-CITIZENS... EVEN IF THEY ARE ILLEGAL IMMIGRANTS.... WE ARE ALL EQUAL IN THE EYES OF THE LAW.
But THIS IS HAPPENING ON SOUTH AFRICAN ARMY LAND AND THIS IS THE ARMY's SHOOTING RANGE......
WHAT HAS HAPPENED????? THE WHOLE BLOODY COUNTRY HAS GONE STUPID........
THIS IS THE REASON THAT SO MANY OF OUR HIGHLY QUALIFIED PEOPLE HAVE LEFT AND GIVEN UP ON OUR BELOVED COUNTRY....
The fact that this squatter/electricity problem has caused the cancellation of the Pistol Shooting Section of the SA Masters Games proves how our pathetic government's soft laws have created a wonderful haven for the unlawful misuse and abuse of everything possible.
I sincerely BELIEVE an in-depth article should go INTERNATIONAL about this disgraceful South African situation. I would love to see a report appearing in all of our national newspapers AND on television..... BUT unfortunately, without having certain proof and accurate details, it would be wrong for anyone to drop this bombshell onto some eager newspaper reporter's desk
Earlier this month (April) during our 2013 National Championships, this loss of electricity caused unbelievable difficulty for the SAPA organisers and it was only with the help of local Pretoria members that a number of generators were brought in so that the Range Officers could operate with electronic targets and the Statistics Team could log in the thousands of scores into their computers.
We can thank those hard-working people every day for their dedication and assistance and time. Some of them have given up shooting at Nationals so that they can dedicate their attention to running the ranges and events..
These are very special people and I thank them sincerely for their commitment to "keeping the show on the road".
The Chairman, Clubs and Members
Natal Pistol Association
It is with the greatest amount of sadness, disgust, disappointment, frustration, anger and many other horrible emotions that I pass on the following message, followed by some of my comments.
"To all Provincial Chairpersons,
The Pistol shooting event which would have been presented during the 8th SA Masters Games in Pretoria from 1 to 4 May 2013, has been cancelled due to the current electricity problem at the SANDF Eeufees Range.
Kindly distribute this e-mail as widely as possible to all Clubs and members alike, to ensure that all are informed.
Your co-operation in this regard is appreciated.
Kind regards,
Mathilda"
Continued from above:
During recent years a number of squatters have set themselves up on the SANDF land adjoining the Defence Force Shooting range, Pretoria. (JUST ACROSS THE ROAD FROM THE VOORTREKKER MONUMENT).
At times the squatters joined their illegal wires onto the main electricity wires leading to the Defence shooting range which caused such a problem that the SANDF have had their own electricity discontinued because of the illegal usage by the squatters.
You might ask questions like "why are they not just removed?" "Why doesn't the Army just kick them off the property" and "WHAT HAPPENED TO THE LAW?"
FORGET ABOUT WHAT YOU ALWAYS BELIEVED WAS THE LAW...... THAT WAS ACTUALLY IN YOUR DREAMS...
REALITY IS NOW.... REALITY IS THE NIGHTMARE.
THIS IS THE NEW AGE.... OUR LAWS PROTECT THESE SQUATTERS EVEN IF THEY ARE DOING A CRIMINAL ACT LIKE STEALING ELECTRICITY... BELIEVE IT OR NOT WE ARE ALL PROTECTED BY THE LAW... WE ALL HAVE RIGHTS..... HONEST PEOPLE OR DISHONEST.... CITIZENS OR NON-CITIZENS... EVEN IF THEY ARE ILLEGAL IMMIGRANTS.... WE ARE ALL EQUAL IN THE EYES OF THE LAW.
But THIS IS HAPPENING ON SOUTH AFRICAN ARMY LAND AND THIS IS THE ARMY's SHOOTING RANGE......
WHAT HAS HAPPENED????? THE WHOLE BLOODY COUNTRY HAS GONE STUPID........
THIS IS THE REASON THAT SO MANY OF OUR HIGHLY QUALIFIED PEOPLE HAVE LEFT AND GIVEN UP ON OUR BELOVED COUNTRY....
The fact that this squatter/electricity problem has caused the cancellation of the Pistol Shooting Section of the SA Masters Games proves how our pathetic government's soft laws have created a wonderful haven for the unlawful misuse and abuse of everything possible.
I sincerely BELIEVE an in-depth article should go INTERNATIONAL about this disgraceful South African situation. I would love to see a report appearing in all of our national newspapers AND on television..... BUT unfortunately, without having certain proof and accurate details, it would be wrong for anyone to drop this bombshell onto some eager newspaper reporter's desk
Earlier this month (April) during our 2013 National Championships, this loss of electricity caused unbelievable difficulty for the SAPA organisers and it was only with the help of local Pretoria members that a number of generators were brought in so that the Range Officers could operate with electronic targets and the Statistics Team could log in the thousands of scores into their computers.
We can thank those hard-working people every day for their dedication and assistance and time. Some of them have given up shooting at Nationals so that they can dedicate their attention to running the ranges and events..
These are very special people and I thank them sincerely for their commitment to "keeping the show on the road".
Tuesday, 9 April 2013
Reading the Wind When Hunting
Thomas Haugland, a Shooters’ Forum member from Norway, is a long-range target shooter and hunter. He has created an interesting video showing how to gauge wind velocities by watching trees, grass, and other natural vegetation. The video commentary is in English, but the units of wind speed (and distance) are metric. Haugland explains: “This is not a full tutorial, but rather a short heads-up to make you draw the lines between the dots yourself”. Here are some conversions that will help when watching the video (thanks Boyd):
.5 m/s = 1.1 mph | 1 m/s = 2.2 mph | 2 m/s = 4.5 mph
3 m/s = 6.7 mph | 4 m/s = 8.9 mph | 5 m/s =11.2 mph
To watch this interesting and worthwhile video, click HERE
(or copy and paste the URL: http://www.accurateshooter.com/shooting-skills/reading-the-wind-when-hunting/)
More Interesting Videos from Norway
There are many other interesting videos on Haugland’s YouTube Channel, including Game Stalking,Precision Reloading, and Tips on how to use a Mildot Reticle on a scope with MOA-based clicks.
Reading the Wind — USAMU Tips
(United States Army Marksmanship Unit)
The term, “Reading the Wind” is misleading. A more apt title might be “The tactical negotiation of varying wind conditions and the limitation of their negative effects on the flight of your bullet.” In this article we will discuss some tactics and techniques that will enhance your abilities to negotiate the wind and (hopefully) add a few points to your score. This article will be divided into two sections: Part One will cover the 200- and 300-yard stages. Part Two will be devoted to the 600-yard stage.
There are as many dimensions to “wind reading” as there are stages to High Power competition. Your tactical mindset, or philosophy, must be different for the 200- and 300-yard rapid-fire stages than it would be for the 600-yard slow-fire. In the slow-fire stages you have the ability to adjust windage from shot to shot, utilizing the location of the previous shot as an indicator. Additionally, a change to the existing conditions can be identified and adjusted for prior to shooting the next shot.
Part 1: Rapid Fire at 200 and 300 Yards
Part 2: 600-Yard Firing
To read the full article click HERE
(Or copy and paste the URL: http://www.accurateshooter.com/shooting-skills/readingwind/)
Horizontal Wind-Drift vs. Distance
OK, if the wind is blowing 10 mph from 9 o’clock and if my horizontal wind deflection is .7 inches at 100 yards, what is the drift at 1000 yards?
Well, roughly speaking, since the target is ten times more distant, the wind-drift must be around 7 inches, maybe a little more since the bullet will be slowing down. Seems reasonable right?
WRONG.
Lateral deflection by a 10mph crosswind is (roughly speaking) a function of the square of the distance. In this example, the TRUE deflection is .7″ times (10×10) — about 70 inches!!
I was going through some back issues of Precision Shooting Magazine and this was explained in detail. Now, I remained skeptical, so I checked my Pejsa Ballistics Calculator, which is just about the most accurate program I’ve found to describe the behavior of high BC bullets in flight.
For a 168 Sierra MK (.308), leaving the muzzle at 2700fps with a .464 BC, the numbers are as follows, with a 10mph, 9 o’clock crosswind:
For my 260 Rem load, 123 Scenar (.547BC), 2930fps, same 10mph conditions, Pejsa predicts:
* for simplicity, I’m calculating 1 moa = 1″ x distance / 100 .
To read the full article click HERE
(Or copy and paste the URL: http://www.accurateshooter.com/shooting-skills/horizontal-wind-drift-vs-distance/)
FREE Ballistics Software: Use the JBM online ballistics program or download Pejsa and PointBlank Software.
Wind Drift by Gerard Schultz. Excellent technical Article which dispells many misconceptions about bullet performance. Useful charts plotting effect of both BC and distance on wind drift.
.5 m/s = 1.1 mph | 1 m/s = 2.2 mph | 2 m/s = 4.5 mph
3 m/s = 6.7 mph | 4 m/s = 8.9 mph | 5 m/s =11.2 mph
To watch this interesting and worthwhile video, click HERE
(or copy and paste the URL: http://www.accurateshooter.com/shooting-skills/reading-the-wind-when-hunting/)
More Interesting Videos from Norway
There are many other interesting videos on Haugland’s YouTube Channel, including Game Stalking,Precision Reloading, and Tips on how to use a Mildot Reticle on a scope with MOA-based clicks.
Reading the Wind — USAMU Tips
(United States Army Marksmanship Unit)
The term, “Reading the Wind” is misleading. A more apt title might be “The tactical negotiation of varying wind conditions and the limitation of their negative effects on the flight of your bullet.” In this article we will discuss some tactics and techniques that will enhance your abilities to negotiate the wind and (hopefully) add a few points to your score. This article will be divided into two sections: Part One will cover the 200- and 300-yard stages. Part Two will be devoted to the 600-yard stage.
There are as many dimensions to “wind reading” as there are stages to High Power competition. Your tactical mindset, or philosophy, must be different for the 200- and 300-yard rapid-fire stages than it would be for the 600-yard slow-fire. In the slow-fire stages you have the ability to adjust windage from shot to shot, utilizing the location of the previous shot as an indicator. Additionally, a change to the existing conditions can be identified and adjusted for prior to shooting the next shot.
Part 1: Rapid Fire at 200 and 300 Yards
Part 2: 600-Yard Firing
To read the full article click HERE
(Or copy and paste the URL: http://www.accurateshooter.com/shooting-skills/readingwind/)
Horizontal Wind-Drift vs. Distance
OK, if the wind is blowing 10 mph from 9 o’clock and if my horizontal wind deflection is .7 inches at 100 yards, what is the drift at 1000 yards?
Well, roughly speaking, since the target is ten times more distant, the wind-drift must be around 7 inches, maybe a little more since the bullet will be slowing down. Seems reasonable right?
WRONG.
Lateral deflection by a 10mph crosswind is (roughly speaking) a function of the square of the distance. In this example, the TRUE deflection is .7″ times (10×10) — about 70 inches!!
I was going through some back issues of Precision Shooting Magazine and this was explained in detail. Now, I remained skeptical, so I checked my Pejsa Ballistics Calculator, which is just about the most accurate program I’ve found to describe the behavior of high BC bullets in flight.
For a 168 Sierra MK (.308), leaving the muzzle at 2700fps with a .464 BC, the numbers are as follows, with a 10mph, 9 o’clock crosswind:
- Drift at 100: .75 moa (3/4″)*
- Drift at 200: 1.57moa (3.14″)
- Drift at 500: 5.06moa (25.3″)
For my 260 Rem load, 123 Scenar (.547BC), 2930fps, same 10mph conditions, Pejsa predicts:
- Drift at 100: .48 moa (1/2″)
- Drift at 500: 2.73 moa (13.65″)
- Drift at 1000: 6.48 moa (64.8″)
* for simplicity, I’m calculating 1 moa = 1″ x distance / 100 .
To read the full article click HERE
(Or copy and paste the URL: http://www.accurateshooter.com/shooting-skills/horizontal-wind-drift-vs-distance/)
FREE Ballistics Software: Use the JBM online ballistics program or download Pejsa and PointBlank Software.
Wind Drift by Gerard Schultz. Excellent technical Article which dispells many misconceptions about bullet performance. Useful charts plotting effect of both BC and distance on wind drift.
Sunday, 7 April 2013
How Canting Affects Accuracy
Canting Effect on Point of Impact
Avoid Inconsistent Canting for Better Accuracy and Higher Scores
Experienced marksmen know they should keep their rifles level when shooting. But they may not understand exactly what happens if they allow their rifle to be canted (tilted left or right), even a few degrees. While the physics are complicated to explain, here’s what you need to know: if you cant your rifle to the left, your shots will impact to the left, and lower, than your point of aim. Likewise, if you cant your rifle to the right, your bullets will impact low and right.
Effects of Rifle Canting
The effects of rifle canting are explained in great detail on the Long Shot Products Ltd. website. There, you’ll find a technical discussion of the Physics of Rifle Canting, plus a page with Sample Targets shot with canted rifles.
Referring to the above illustration, the Long Shot Products article explains: “Notice how the trajectory of the vertical hold stays within the vertical plane, so when the projectile drops, it drops into the line of sight and down to the center of the target. The trajectory of the cant hold does not achieve the same height as the trajectory of the vertical hold and the projectile diverges from the line of sight, thereby missing the target.”
Bryan Litz confirms Tubb’s observation. Bryan tells us that, as a general rule of thumb (for common cartridges), a 1° cant will produce five (5) inches of lateral displacement at 1000 yards. Thus, if you cant your rifle just 8°, the POI would move 40″ from the center of the target, putting the shot off the edge of a 72″-wide target.
Remember that you must maintain the exact same amount of rifle cant from shot to shot. Yes, some iron sights shooters do tilt their rifle slightly to achieve a better hold or to index their sights better. However, these shooters do not changethe tilt from shot to shot — the amount of cant remains the same on every shot.
When shooting prone with a scoped rifle it’s probably best to keep the rifle dead level, with the scope’s vertical crosshair straight up and down. Use a rifle-mounted bubble level to maintain a level hold, and avoid canting the gun either to the left or to the right. Affordable bubble levels that mount to your scope or scope rail can be purchased from Brownells and other vendors, starting at about $15.00.
Test Targets Reveal Cant Errors
The Long Shot Products Ltd. website also displays actual Test Targets showing the effects of canting error. These targets were shot with air rifles and rimfire rifles, but the same effects can and will occur with centerfire rifles. Shown below is a target shot at 50 yards with a Feinwerkbau .22LR match rifle using RWS Match ammo (1012 fps MV). As you can see, canting the rifle 20 degrees to the left produced a huge movement of the point of impact. The shots from the canted rifle impacted 1.81″ Left, and 0.6″ below the point of aim.
Further reading
Cures for Vertical Stringing
Vertical in your shot strings can result from myriad gear issues and gun-handling mistakes. Speedy Gonzalez, noted shooter, gunsmith and recent inductee into the Benchrest Hall of Fame, offers these pearls of wisdom. Try to isolate one item at a time as you work to improve your groups.
Link: http://www.accurateshooter.com/shooting-skills/cures-for-vertical-stringing/
More Affordable Anti-Cant Alternatives
If you don’t need to make angled shots, you can get a simple rail-mounted B-Square bubble level. Mounting Solutions Plus offers a tube-mounted anti-cant device with bubble level on top. If you prefer the bubble level on the side (for easier viewing) U.S. Optics makes a sturdy, rail-mount bubble level.
Article source: http://www.accurateshooter.com/optics/canting-effect-on-point-of-impact/
Avoid Inconsistent Canting for Better Accuracy and Higher Scores
Experienced marksmen know they should keep their rifles level when shooting. But they may not understand exactly what happens if they allow their rifle to be canted (tilted left or right), even a few degrees. While the physics are complicated to explain, here’s what you need to know: if you cant your rifle to the left, your shots will impact to the left, and lower, than your point of aim. Likewise, if you cant your rifle to the right, your bullets will impact low and right.
Effects of Rifle Canting
The effects of rifle canting are explained in great detail on the Long Shot Products Ltd. website. There, you’ll find a technical discussion of the Physics of Rifle Canting, plus a page with Sample Targets shot with canted rifles.
Referring to the above illustration, the Long Shot Products article explains: “Notice how the trajectory of the vertical hold stays within the vertical plane, so when the projectile drops, it drops into the line of sight and down to the center of the target. The trajectory of the cant hold does not achieve the same height as the trajectory of the vertical hold and the projectile diverges from the line of sight, thereby missing the target.”
The Long-Shot article makes two other important points. First, cant error increases with distance, and second, cant-induced windage errors are worsened by mounting your scope high above the bore axis.“This component of cant error becomes more significant at more distant targets due to the increased original included angle between the line of sight axis and the bore axis (more elevation compensation) at the vertical hold. Use of large-diameter objective scopes, mounted high off the barrel, exacerbates the cant error problem. To keep the scope elevation knobs centered for maximum adjustment, precision shooters sometimes use elevation-compensated scope mounting rings or bases. Although this solves the adjustment problem, it greatly exaggerates cant error because the distance between the bore axis and the line of sight axis increases and the included angle between the sight axis and the bore is larger, producing more windage error when canting.”
Effects of Rifle Canting at Long Range — David Tubb Explains
Eleven-Time NRA National High Power Champion David Tubb knows a bit about long-range shooting. One of the key factors in long-range accuracy is making sure that the tilt/cant of your rifle does not change throughout your shot string. In the clip below, the first in McMillan’s Master Class Video series, David Tubb explains the importance of keeping your rifle level. He explains that, at 1000 yards, your Point of Impact can change dramatically by canting the rifle either right or left. David states that, when shooting at 1000 yards, if your rifle is level and your shot is centered-up on a 72″ (six-foot) square target, you can actually put your next shot OFF PAPER by canting your rifle. That means you can move Point of Impact (POI) three feet or more, just by canting your rifle!Bryan Litz confirms Tubb’s observation. Bryan tells us that, as a general rule of thumb (for common cartridges), a 1° cant will produce five (5) inches of lateral displacement at 1000 yards. Thus, if you cant your rifle just 8°, the POI would move 40″ from the center of the target, putting the shot off the edge of a 72″-wide target.
David explains that, after one of his students has made two or three 1000-yard, X-Ring hits with a LEVEL rifle, “then I’ll have him take his rifle, and cant it to the right. I’ll have him shoot a shot. He will MISS the six-foot-square frame off to the right. Then I’ll have him cant his gun to the left and shoot another shot. He will miss the six-foot-square frame to the left.”Rifle Hold and Canting — Consistency Counts
Remember that you must maintain the exact same amount of rifle cant from shot to shot. Yes, some iron sights shooters do tilt their rifle slightly to achieve a better hold or to index their sights better. However, these shooters do not changethe tilt from shot to shot — the amount of cant remains the same on every shot.
When shooting prone with a scoped rifle it’s probably best to keep the rifle dead level, with the scope’s vertical crosshair straight up and down. Use a rifle-mounted bubble level to maintain a level hold, and avoid canting the gun either to the left or to the right. Affordable bubble levels that mount to your scope or scope rail can be purchased from Brownells and other vendors, starting at about $15.00.
Test Targets Reveal Cant Errors
The Long Shot Products Ltd. website also displays actual Test Targets showing the effects of canting error. These targets were shot with air rifles and rimfire rifles, but the same effects can and will occur with centerfire rifles. Shown below is a target shot at 50 yards with a Feinwerkbau .22LR match rifle using RWS Match ammo (1012 fps MV). As you can see, canting the rifle 20 degrees to the left produced a huge movement of the point of impact. The shots from the canted rifle impacted 1.81″ Left, and 0.6″ below the point of aim.
Further reading
Cures for Vertical Stringing
Vertical in your shot strings can result from myriad gear issues and gun-handling mistakes. Speedy Gonzalez, noted shooter, gunsmith and recent inductee into the Benchrest Hall of Fame, offers these pearls of wisdom. Try to isolate one item at a time as you work to improve your groups.
Link: http://www.accurateshooter.com/shooting-skills/cures-for-vertical-stringing/
More Affordable Anti-Cant Alternatives
If you don’t need to make angled shots, you can get a simple rail-mounted B-Square bubble level. Mounting Solutions Plus offers a tube-mounted anti-cant device with bubble level on top. If you prefer the bubble level on the side (for easier viewing) U.S. Optics makes a sturdy, rail-mount bubble level.
Article source: http://www.accurateshooter.com/optics/canting-effect-on-point-of-impact/
Saturday, 6 April 2013
Standing Position Shooting Technique
Standing and Trigger Control
By SGT Brandon Green, USAMU Service Rifle Team Member
The CMP webzine, The First Shot, currently features an excellent article for any rifleman (hunter or competitor) who employs the standing position. Authored by USAMU Team member Sgt. Brandon Green, the story covers rifle hold, body positioning, and trigger control. Sgt. Green writes: “We’ve all been there—on the two hundred yard line and in our three-minute prep period. As you stand there looking through your sights, you just can’t seem to make them stay in the center of your target or even close for that matter. You know that your three minutes are running out quickly, so what are you going to do? This is the time when a lot of shooters start to come unraveled….We all know how to stand up, but it’s the standing still part that gives us trouble most of the time.”
Sgt. Green continues: “We will start our position rebuild at the feet. You normally want your feet about shoulder width apart and perpendicular to the target. Some shooters like to keep their weight evenly distributed between the heels and balls of their feet, but this may not be the best position for you. I normally try to find a place on the firing line where my toes are just slightly higher than my heels, maybe a 1/4 to 1/2 inch higher. With my toes slightly higher, I feel a little more of the pressure on the balls of my feet. This usually helps me eliminate some of the back and forth movement in my position by inducing a little tension in my calf muscles.
At this point I will check for excess tension in other parts of my legs. I notice that excess tension in my upper legs can also cause me to sway back and forth more than usual. By rotating each foot in or out, I can usually find a position that will eliminate this excess tension and help my legs feel more relaxed. I then check the tension in my knees. I don’t shoot with my knees locked, but they aren’t exactly bent either. I find where they are comfortable and stick with it. Now that my legs are at a good starting point, I move up to my hips and waist. I normally shoot with my hips perpendicular to the target and twist at the waist slightly. This is more of an international style rifle position than a traditional highpower position, but it is very comfortable and relaxed for me. With my waist only slightly twisted, I can rest my forward arm almost directly on my hip bone instead of bringing it around and resting it on my ribs.” [Continued...]
Read the full article here: http://www.odcmp.org/1007/default.asp?page=USAMU_STANDING
By SGT Brandon Green, USAMU Service Rifle Team Member
The CMP webzine, The First Shot, currently features an excellent article for any rifleman (hunter or competitor) who employs the standing position. Authored by USAMU Team member Sgt. Brandon Green, the story covers rifle hold, body positioning, and trigger control. Sgt. Green writes: “We’ve all been there—on the two hundred yard line and in our three-minute prep period. As you stand there looking through your sights, you just can’t seem to make them stay in the center of your target or even close for that matter. You know that your three minutes are running out quickly, so what are you going to do? This is the time when a lot of shooters start to come unraveled….We all know how to stand up, but it’s the standing still part that gives us trouble most of the time.”
Sgt. Green continues: “We will start our position rebuild at the feet. You normally want your feet about shoulder width apart and perpendicular to the target. Some shooters like to keep their weight evenly distributed between the heels and balls of their feet, but this may not be the best position for you. I normally try to find a place on the firing line where my toes are just slightly higher than my heels, maybe a 1/4 to 1/2 inch higher. With my toes slightly higher, I feel a little more of the pressure on the balls of my feet. This usually helps me eliminate some of the back and forth movement in my position by inducing a little tension in my calf muscles.
At this point I will check for excess tension in other parts of my legs. I notice that excess tension in my upper legs can also cause me to sway back and forth more than usual. By rotating each foot in or out, I can usually find a position that will eliminate this excess tension and help my legs feel more relaxed. I then check the tension in my knees. I don’t shoot with my knees locked, but they aren’t exactly bent either. I find where they are comfortable and stick with it. Now that my legs are at a good starting point, I move up to my hips and waist. I normally shoot with my hips perpendicular to the target and twist at the waist slightly. This is more of an international style rifle position than a traditional highpower position, but it is very comfortable and relaxed for me. With my waist only slightly twisted, I can rest my forward arm almost directly on my hip bone instead of bringing it around and resting it on my ribs.” [Continued...]
Read the full article here: http://www.odcmp.org/1007/default.asp?page=USAMU_STANDING
Wednesday, 3 April 2013
Firearm Negligence - The importance of proper training
This is a compilation video I put together to show students in my firearms classes. NONE of these video clips are mine, all credit goes to the original owners. They were pilfered from individual videos and other compilations.
Shown are negligent discharges, improper equipment checks and uses, improper attire and using a firearm that the person is incapable to use or unfamiliar with.
The intent of this compilation is to be able to show students some relative examples while discussing firearm safety and responsibility. Some of the clips have been included specifically to spark or demonstrate instruction in particular areas of safety, sometimes through exaggeration.
Since these clips are not my own, I felt it was only proper to share them back out through YouTube for others to be able to use them as I am intending to use them.
Source: http://www.youtube.com/watch?v=Et33bbA0GeM
Shown are negligent discharges, improper equipment checks and uses, improper attire and using a firearm that the person is incapable to use or unfamiliar with.
The intent of this compilation is to be able to show students some relative examples while discussing firearm safety and responsibility. Some of the clips have been included specifically to spark or demonstrate instruction in particular areas of safety, sometimes through exaggeration.
Since these clips are not my own, I felt it was only proper to share them back out through YouTube for others to be able to use them as I am intending to use them.
Source: http://www.youtube.com/watch?v=Et33bbA0GeM
Marlin Firearms Closes In North Haven, Ending 141 Years Of Manufacturing In Connecticut
by Brock Townsend
A half-dozen workers were in otherwise empty offices Friday at The Marlin Firearms Co. as the company wound down 141 years of manufacturing in Connecticut.
A security phone at the visitor's gate was unattended next to a large barren parking lot off Bailey Road near I-91. A reception room that resembles a ski lodge, complete with a fireplace, was dark. The few people left working Friday declined to comment, but one employee said there were six people inside and that Friday was their last day of work.
Marlin was acquired in 2008 by Remington Arms Co. Inc., which is a subsidiary of Freedom Group Co. of Madison, N.C. Three years ago, Marlin employed 345 people at its headquarters in North Haven and 225 in Gardner, Mass., at the former Harrington and Richardson plant that Marlin had acquired.
"I think it's a huge loss," said Larry Lazaroff, co-owner of Arnold's Jewelers, a longtime local business in the North Haven Shopping Center.
He cited Pratt & Whitney closing its North Haven plant in 1993, saying that the loss of any major employer reduces the customer base for local businesses.
Remington said in March 2010 that it would close the North Haven Marlin plant, which had 265 employees at that point. The company has been at its 225,000-square-foot facility on a 23-acre site in North Haven since 1968. Before that, it was on Willow Street in New Haven.
Marlin was founded when John M. Marlin left Colt in 1870 and started manufacturing his own line of revolvers and derringers. In 1924, Frank Kenna, an attorney, bought the company at auction and the Kenna family owned Marlin until its sale to Remington.
Marlin was the rifle of choice for famous sharpshooter Annie Oakley, who was in William "Buffalo Bill" Cody's circus.
Source: http://freenorthcarolina.blogspot.com/2013/04/marlin-firearms-closes-in-north-haven.html
A half-dozen workers were in otherwise empty offices Friday at The Marlin Firearms Co. as the company wound down 141 years of manufacturing in Connecticut.
A security phone at the visitor's gate was unattended next to a large barren parking lot off Bailey Road near I-91. A reception room that resembles a ski lodge, complete with a fireplace, was dark. The few people left working Friday declined to comment, but one employee said there were six people inside and that Friday was their last day of work.
Marlin was acquired in 2008 by Remington Arms Co. Inc., which is a subsidiary of Freedom Group Co. of Madison, N.C. Three years ago, Marlin employed 345 people at its headquarters in North Haven and 225 in Gardner, Mass., at the former Harrington and Richardson plant that Marlin had acquired.
"I think it's a huge loss," said Larry Lazaroff, co-owner of Arnold's Jewelers, a longtime local business in the North Haven Shopping Center.
He cited Pratt & Whitney closing its North Haven plant in 1993, saying that the loss of any major employer reduces the customer base for local businesses.
Remington said in March 2010 that it would close the North Haven Marlin plant, which had 265 employees at that point. The company has been at its 225,000-square-foot facility on a 23-acre site in North Haven since 1968. Before that, it was on Willow Street in New Haven.
Marlin was founded when John M. Marlin left Colt in 1870 and started manufacturing his own line of revolvers and derringers. In 1924, Frank Kenna, an attorney, bought the company at auction and the Kenna family owned Marlin until its sale to Remington.
Marlin was the rifle of choice for famous sharpshooter Annie Oakley, who was in William "Buffalo Bill" Cody's circus.
Source: http://freenorthcarolina.blogspot.com/2013/04/marlin-firearms-closes-in-north-haven.html
Sunday, 31 March 2013
How to Sight in a Scope - Step by Step Guide
A Gundata.org article
Author: Jason Brumett
The following is a step by step guide on how to sight in a scope, also known as zeroing in. Even if you've sighted one in before this post could be used as a refresher.
The article details Dominant Eye Issues, Breathing Techniques, Picking a Scope, Necessary Equipment, Target, Rifle Position, and Shot Group.
Hope this is of some use to you, if it is be sure to Share, Like, Tweet, and Email this article to your friends.
Dominant Eye
For first time shooters finding your dominant eye is important. Some people are under the impression that using your dominant arm is required for shooting a weapon, but it doesn't really matter which arm you use to shoot with as long as you use your dominant eye.
- Make a triangle with your hands facing flat as if you were going to do a diamond push-up.
- Pick an object in the distance such as a picture on a wall or a fire alarm on the ceiling.
- Keeping your arms at a 90 degree angle; look through the triangle you made with your hands and slowly extend your arms outward while staying focused on the object.
- Once your arms are fully extended close each eye one at a time to see which is centered on the object-that will be your dominant eye and the side of your body that you place the butt of your rifle on when shooting.
Breathing Technique
Breathing is an important part of shooting to make sure each shot is well-placed. Practicing breathing before going to the range can help cut down on the time it takes to zero in a rifle. Shot groups are used in groups of three to determine how a scope needs to be adjusted to hit the center of a target. If one shot is a few inches off compared to the other two, then that has to do more with breathing than anything else. This breathing method can be put into practice while at home.
- Close your eyes and focus on when you inhale and exhale
- Each time you exhale there's a small pause before you inhale. This is when your body is balanced and is the best time for each shot to be fired.
- Once you can determine the pausing point between your breathing use that to imagine firing your rifle each time it happens.
- Firing a rifle during this pausing point will eliminate any erratic shot groups to help zero in a rifle.
Picking a Scope
f you have a bolt action rifle make sure to bore sight your rifle before you go to the range after you have mounted the scope.
When mounting a scope make sure to use the proper mount and screws to fit the rifle that is being fired. This will eliminate any potential problems with the scope becoming dislodged when a rifle kicks.
Necessary Equipment
Call ahead if unsure what type of lanes and materials the range you are going to has on its grounds. Some basic items to bring with you can help the process go more quickly.
- Padding for your shoulder to help shield from a rifle kick
- Rifle Rest or Sand Bags to use as a turret for better shot groups
- Enough ammo to zero in the rifle. Try to get ammo from the same lot number which can be found on the side of each box.
- Screwdrivers for adjusting the scope
- 25 to 100 Meter targets
- Black Marker to mark your previous shots
- Binoculars to look down range to see each shot group
Target
Targets are usually set-up for 25 meters for first group and 100 meters to zero in a rifle for maximum point blank range. Each three round shot group should be aimed at the center bulls-eye for the duration of the zero in process. A shot group consists of three well-placed shots, which in turn should be marked to see which direction you need to move the elevation and windage on the scope.
Rifle Position
Rifle position is important to maintain. Once finding a comfortable position to zero in a rifle, make sure it is the same position you fire from every single time.
- Make sure to have the rifle butt firmly placed in then soft tissue area on the shoulder just below your clavicle. Don't place it directly into your clavicle or you could cause damage to your shoulder/bone.
- The opposite arm you are using should be under the forearm of the rifle and the end of the rifle forearm should be on the rifle rest or sandbags.
- A well placed grip behind the trigger area of the rife to ensure it doesn't move during each shot. Do not place your finger on the trigger until you are ready to shoot.
- Use the soft padding just below your distal phalange on your index finger to fire each shot. It should take barely any effort to squeeze each shot on the trigger if done correctly.
- Place your nose or the side of your cheek on the barrel of the rifle. Do not get directly in front of the scope and bolt, or you will get smacked in the face after each shot from the recoil. Once you have found a comfortable spot to place your face for firing position this should be where you place your face EVERY single time for each shot group.
Shot Group
Once you have determined your shot group in relation to the center of the target you can then adjust the elevation and windage on the scope. The scope should have directions on how many clicks per-meters it should be moved.
For example: if you have a shot group in the top-right you would adjust the scope down and left. Continue to do this until you get three (9 Total shots) well-placed shot groups in the center of the target.
100 Meter Target
The final step is to determine the maximum point blank range. Set-up a target at 100 meters and using the same method of shot groups. Long range rifles (.243 w/90 Grain bullet or .270 w/130 grain) should be adjusted to land 2.5 inches above the center of the target and medium range rifles (30-30 w/150 grain or .300 Savage w/165 grain) should land 3 inches above the target. Once the elevation and windage is correct and you have three more (9 total shots) well-placed groups then you have successfully zeroed in your rifle.
Source: http://gundata.org/blog/post/how-to-sight-in-scope/
Friday, 29 March 2013
Secondary Ammo Pressure Spikes
by Nick Leghorn
When a gun goes off, the expanding gasses created by the burning gunpowder pressurize the chamber and force the bullet down the barrel. There’s all sorts of interesting science behind what the maximum pressure of the ammunition can be before the chamber ruptures, and what the proper pressure is for the best and most consistent grouping. But that all assumes a “normal” pressure wave. What happens if your ammunition isn’t actually conforming to that normal curve? And is a secondary spike even possible? . . .
Let me start by talking about measuring those spikes in the first place.
The standard method for measuring the pressure in a firearm’s chamber is by direct observation. A hole is drilled into the chamber, and a small sensor is placed in the hole. Historically the sensor was made of either copper or lead, but more common today is a piezoelectric sensor that translates pressure into electrical current.
The problem with direct observation is that it’s expensive and you have to sacrifice a barrel to the process. However, Charlie Sisk at Sisk Rifles has a pretty smart way of doing pressure testing on the cheap. Instead of directly measuring the pressure in the barrel, he simply measures the expansion of the metal surrounding the chamber (since the metal deforms slightly as the gun is pressurized) using some very accurate sensors and computers. Through years of testing, he has perfected the formula for determining chamber pressure based on metal expansion.
This is a “normal” pressure curve. The pressure in the chamber increases as the powder burns, then decreases as the bullet moves down the barrel and increases the available volume. Eventually the bullet leaves the barrel and the pressure drops off.
However, Charlie started to notice that sometimes when he was working up a load he’d get a secondary spike. One that didn’t make any sense.
You expect the first spike from the initial gunpowder burn, but where the hell did that second pressure spike come from? It didn’t make sense.
Naturally, Charlie kept testing. As a result, he can create a secondary pressure spike whenever he wants just by varying the load parameters. The ability to repeat the results on demand indicate that this isn’t some kind of instrumentation fluke. There really is a secondary spike going on in some loads. And not just in handloads — Charlie has seen this same pattern in some commercial ammunition, too.
“So what?” I hear you say. “That’s interesting, but what does that have to do with me?” Well, turns out that secondary spikes might have some safety implications.
Charlie was playing around with a new, full-length barrel (26 inches, I believe) in his gunsmithing shop and creating some secondary spikes in order to figure out what was going on. After the seventh round, the shot sounded… different. When he looked, it turns out that the front five inches or so of his barrel had fallen off.
He repeated the same test with three more barrels, and all three were cleanly chopped off at 21.6 inches exactly. Secondary pressure spikes caused spontaneous barrel shortening. Or, put another way, they blasted off the front of his barrel.
The cause of these spikes is still unknown. But that doesn’t mean there isn’t a theory. The best of those is that the water vapor in the atmosphere of the barrel forms a “vapor cone” around the bullet, much like it does around aircraft breaking the sound barrier. That vapor cone, as the theory postulates, creates increased drag and therefore a pressure spike. Again, it’s still just a theory.
Charlie is continuing to do his testing, and others have picked up on the issue, too. There’s a paper on the subject currently being written by a couple of other internal ballistics boffins, so we should have some more hard evidence of what’s going on shortly. Until then, its just another fascinating mystery.
About Nick Leghorn
Nick Leghorn is a gun nerd living and working in San Antonio, Texas. In his free time, he's a competition shooter (USPSA, 3-gun and NRA High Power), EMT-B and enjoys mixing statistics and science with firearms. Now on sale: Getting Started with Firearms by yours truly!
Source: http://www.thetruthaboutguns.com/2013/03/foghorn/secondary-pressure-spikes-in-ammunition/
When a gun goes off, the expanding gasses created by the burning gunpowder pressurize the chamber and force the bullet down the barrel. There’s all sorts of interesting science behind what the maximum pressure of the ammunition can be before the chamber ruptures, and what the proper pressure is for the best and most consistent grouping. But that all assumes a “normal” pressure wave. What happens if your ammunition isn’t actually conforming to that normal curve? And is a secondary spike even possible? . . .
Let me start by talking about measuring those spikes in the first place.
The standard method for measuring the pressure in a firearm’s chamber is by direct observation. A hole is drilled into the chamber, and a small sensor is placed in the hole. Historically the sensor was made of either copper or lead, but more common today is a piezoelectric sensor that translates pressure into electrical current.
The problem with direct observation is that it’s expensive and you have to sacrifice a barrel to the process. However, Charlie Sisk at Sisk Rifles has a pretty smart way of doing pressure testing on the cheap. Instead of directly measuring the pressure in the barrel, he simply measures the expansion of the metal surrounding the chamber (since the metal deforms slightly as the gun is pressurized) using some very accurate sensors and computers. Through years of testing, he has perfected the formula for determining chamber pressure based on metal expansion.
This is a “normal” pressure curve. The pressure in the chamber increases as the powder burns, then decreases as the bullet moves down the barrel and increases the available volume. Eventually the bullet leaves the barrel and the pressure drops off.
However, Charlie started to notice that sometimes when he was working up a load he’d get a secondary spike. One that didn’t make any sense.
You expect the first spike from the initial gunpowder burn, but where the hell did that second pressure spike come from? It didn’t make sense.
Naturally, Charlie kept testing. As a result, he can create a secondary pressure spike whenever he wants just by varying the load parameters. The ability to repeat the results on demand indicate that this isn’t some kind of instrumentation fluke. There really is a secondary spike going on in some loads. And not just in handloads — Charlie has seen this same pattern in some commercial ammunition, too.
“So what?” I hear you say. “That’s interesting, but what does that have to do with me?” Well, turns out that secondary spikes might have some safety implications.
Charlie was playing around with a new, full-length barrel (26 inches, I believe) in his gunsmithing shop and creating some secondary spikes in order to figure out what was going on. After the seventh round, the shot sounded… different. When he looked, it turns out that the front five inches or so of his barrel had fallen off.
He repeated the same test with three more barrels, and all three were cleanly chopped off at 21.6 inches exactly. Secondary pressure spikes caused spontaneous barrel shortening. Or, put another way, they blasted off the front of his barrel.
The cause of these spikes is still unknown. But that doesn’t mean there isn’t a theory. The best of those is that the water vapor in the atmosphere of the barrel forms a “vapor cone” around the bullet, much like it does around aircraft breaking the sound barrier. That vapor cone, as the theory postulates, creates increased drag and therefore a pressure spike. Again, it’s still just a theory.
Charlie is continuing to do his testing, and others have picked up on the issue, too. There’s a paper on the subject currently being written by a couple of other internal ballistics boffins, so we should have some more hard evidence of what’s going on shortly. Until then, its just another fascinating mystery.
About Nick Leghorn
Nick Leghorn is a gun nerd living and working in San Antonio, Texas. In his free time, he's a competition shooter (USPSA, 3-gun and NRA High Power), EMT-B and enjoys mixing statistics and science with firearms. Now on sale: Getting Started with Firearms by yours truly!
Source: http://www.thetruthaboutguns.com/2013/03/foghorn/secondary-pressure-spikes-in-ammunition/
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