Comparing Recoil Reduction
Anyone who has put 500 rounds of major
centerfire ammunition downrange in an afternoon of Prairie Dog hunting
will understand the value of recoil reduction. Actually, there
are two separate issues.
One issue is that a shooter doesn't want his target Prairie Dog to disappear out of the field of view in his rifle scope when the shot is discharged. There is nothing like seeing the shot strike to learn about distance shooting, especially trajectory and wind reading and correction. To climb the learning curve of distance shooting, it is essential to obtain the feedback of bullet strike. If the shooter is lucky enough to have a dedicated spotter to call each shot strike, that's great. For the rest of us, we need to see that bullet strike through the scope. With most center fire rifles and the magnification of scopes used for distance shooting, the target disappears from the scope upon discharge. Shooters using dangerous-game rifles will sympathize with this because of their need for shot-to-shot recovery.
The other issue is the punishment of recoil. Most anyone can stand to shoot five or ten rounds or major center fire ammunition, even in a relatively light rifle. But, just wander into a serious Prairie Dog town with plenty of ammunition for a serious rifle, and accuracy can soon taper off because of the anticipated pain of the next shot's recoil. It is not unusual to put several hundred rounds downrange in one day of good Prairie Dog shooting. Shooting this much serious ammunition, even in a heavy field rifle, can be a real problem for normal people who are not Orangutans.
To solve these problems, recoil reduction is in order. Fortunately, there are some very good solutions to recoil available. This experiment attempts to quantify the recoil reduction benefits of low-end and high-end systems.
First, let's define some terms. By "recoil" we are not speaking of some esoteric term of physics defined only by equations. We are talking about felt recoil, or perceived recoil. This means the effect on the shooter - the person squeezing the trigger. Even this definition of recoil has more than one component. To keep with our intended lay simplicity, let's call them the velocity, size and the duration of recoil. All can be important in how they effect the flesh and bone of a shooter's shoulder. A very strong push of long duration might push your shoulder out of alignment with the rifle, but with little pain. A strong recoil impulse of short distance would also be easy to live with. But, save us from the strong recoil impulse of long duration and extended distance. This might be true of a .338 magnum in a mountain weight rifle, certainly not a first choice for lots of shooting in one day.
So, how can we measure the recoil that concerns shooters in high volume or precision shooting? Of course, there are precision instruments that can be used or devised to measure recoil. However, the simple method used in this experiment was to see how far an unsupported rifle will slid on a carpeted shooting bench upon discharge. This test has proven to be able to achieve consistent results. Even if not an exact measure of the recoil of physics, or of shooter-felt recoil, it does offer a demonstration that provides approximate information about how various recoil reduction methods compare, and the extent that recoil under different conditions might affect a shooter. The information provided by this method of testing also seems to correlate well with the subjective experience of shooters testing the same recoil reduction systems.
One issue is that a shooter doesn't want his target Prairie Dog to disappear out of the field of view in his rifle scope when the shot is discharged. There is nothing like seeing the shot strike to learn about distance shooting, especially trajectory and wind reading and correction. To climb the learning curve of distance shooting, it is essential to obtain the feedback of bullet strike. If the shooter is lucky enough to have a dedicated spotter to call each shot strike, that's great. For the rest of us, we need to see that bullet strike through the scope. With most center fire rifles and the magnification of scopes used for distance shooting, the target disappears from the scope upon discharge. Shooters using dangerous-game rifles will sympathize with this because of their need for shot-to-shot recovery.
The other issue is the punishment of recoil. Most anyone can stand to shoot five or ten rounds or major center fire ammunition, even in a relatively light rifle. But, just wander into a serious Prairie Dog town with plenty of ammunition for a serious rifle, and accuracy can soon taper off because of the anticipated pain of the next shot's recoil. It is not unusual to put several hundred rounds downrange in one day of good Prairie Dog shooting. Shooting this much serious ammunition, even in a heavy field rifle, can be a real problem for normal people who are not Orangutans.
To solve these problems, recoil reduction is in order. Fortunately, there are some very good solutions to recoil available. This experiment attempts to quantify the recoil reduction benefits of low-end and high-end systems.
First, let's define some terms. By "recoil" we are not speaking of some esoteric term of physics defined only by equations. We are talking about felt recoil, or perceived recoil. This means the effect on the shooter - the person squeezing the trigger. Even this definition of recoil has more than one component. To keep with our intended lay simplicity, let's call them the velocity, size and the duration of recoil. All can be important in how they effect the flesh and bone of a shooter's shoulder. A very strong push of long duration might push your shoulder out of alignment with the rifle, but with little pain. A strong recoil impulse of short distance would also be easy to live with. But, save us from the strong recoil impulse of long duration and extended distance. This might be true of a .338 magnum in a mountain weight rifle, certainly not a first choice for lots of shooting in one day.
So, how can we measure the recoil that concerns shooters in high volume or precision shooting? Of course, there are precision instruments that can be used or devised to measure recoil. However, the simple method used in this experiment was to see how far an unsupported rifle will slid on a carpeted shooting bench upon discharge. This test has proven to be able to achieve consistent results. Even if not an exact measure of the recoil of physics, or of shooter-felt recoil, it does offer a demonstration that provides approximate information about how various recoil reduction methods compare, and the extent that recoil under different conditions might affect a shooter. The information provided by this method of testing also seems to correlate well with the subjective experience of shooters testing the same recoil reduction systems.
The primary rifle used was a Remington 700, Police Sniper, chambered in .308 Winchester, although other rifles were tested and will be discussed. This rifle with bull barrel and a heavy stock weighs in for the experiment at 10 pounds (NOTE: GET EXACT WEIGHT), and is equipped with a Harris bipod.
After evaluating various methods to measure recoil, it was determined to simply measure how far this rifle would slide on a carpeted shooting bench upon recoil. The 700 was set on the bench, bipod extended and flush with a taped white line on the bench. The plan is to measure how far the front of the bipod leg moves from the line upon recoil. The ammunition used is handloaded once-fired, Lake City military brass, pushing the Hornady A-Max, 168-grain bullet at 2,780 FPS.
The 700 was tested first with the JP muzzle brake, made by JP Rifles (jprifles.com).
The bipod was set up against the white line as was the tip of the yardstick.
The trigger was squeezed gently, without interfering with the movement of the rifle.
The 700 moved back 5 3/4 inches.
The JP brake was removed from the muzzle of the 700.
The test was repeated with no brake on the rifle.
This time, the rifle moved 14 3/4 inches.
Because it was available, the same test was tried with a 14-pound DPMS Panther in .308, with a Miculek muzzle brake, same ammunition. The Miculek brake looks like this.
The DPMS moved 6 3/4 inches.
The next test will be with horizontal boring of the 700 barrel to produce built-in muzzle brake. Here is an example of this system on a 30-caliber rifle with a thinner barrel than the 700. After these 3/8" holes are drilled horizontally through the barrel, the barrel is counterbored at .315" to clear the cross-bore cuts and re-crown the barrel.
More coming soon.