Limbsaver Air Tech Recoil Pads

[truck driver]

Been look at replacing the recoil pad or should I say brick on my Remington 700 Classic 35 Whelen. I went to the Sims Vibration web site and looked at these pads. There has been a lot of problems with the old products but it seems that has been taken care of and the new Air Tech pad is supposed to cut recoil by 70%. I would like to here about some real life experiences with this product, has anyone used these and what do you think about them.gun)

 

[SidecarFlip]

Looked at your screen name and it reminded me that I have a nice tire thumper in the closet that takes a 410 shotgun shell. Thumps tires and thumps *** too.

 

[truck driver]

Ya I drive trucks. Been doing it for forty years too long.

 

[Dosh]

Driver, have put them on about a dozen rifles and they are tops. I have found to get the best fit, take the old thumper to a shop or store that has a selection of the Limbsaver pads. Find the model # that best fits your old thumper. If the holes don't match up just drill new ones after carefully marking the spots. Good luck

 

[J E Custom]

Been look at replacing the recoil pad or should I say brick on my Remington 700 Classic 35 Whelen. I went to the Sims Vibration web site and looked at these pads. There has been a lot of problems with the old products but it seems that has been taken care of and the new Air Tech pad is supposed to cut recoil by 70%. I would like to here about some real life experiences with this product, has anyone used these and what do you think about them.gun)

I have done lots of testing for muzzle brakes and recoil reducing devices and in the process did some comparison of different recoil pads.

all a recoil pad does is to distribute the recoil over a large area. all of the different types of
recoil pads only reduced actual recoil from 1 to two foot pounds. 70 % recoil reduction is impossible
for all but the very best muzzle brake.

On my web site I have all of the different recoil devices and there actual performance that may help to
understand the difference in these devices.

www.jecustom.com - FAQ's

J E CUSTOM

 

[truck driver]

Thanks JE, I was just quoting what they published on their web page. The factory pad has become hard and usless for any recoil reduction. The dang thing got on the shoulder bone and hurt like heck. I had to stop shooting. I'm not recoil shy just don't care for the bruises and pain.

 

[SidecarFlip]

Ya I drive trucks. Been doing it for forty years too long.

We probably would not see eye to eye on much transportation related. I'm a safety and compliance officer foir a very large private carrier and I'm a State and Federally certified examiner/trainer.

I hear great stories and believe little.

 

[J E Custom]

Thanks JE, I was just quoting what they published on their web page. The factory pad has become hard and usless for any recoil reduction. The dang thing got on the shoulder bone and hurt like heck. I had to stop shooting. I'm not recoil shy just don't care for the bruises and pain.

I hear you !!!

I just have trouble with outrageous claims. That is the reason we tested with a recoil device,
perception was not good for comparisons and manufactures claims are often inflated because most people can
nether confirm or deny these claims.

I also thought the mercury devices were more efficient until we tasted them and found that a
weight the same as the mercury installed was almost immeasurable from each other for
recoil reduction. So if the mercury device weighted 1 pound and we added a 1 pound weight the recoil was almost the same, so it looks like the weight increase is where the reduction was realized.

A good recoil pad truly makes a difference in felt recoil but does not reduce it by very much.

I replace the old iron but plates on lots of military rifles and they feel totally different even though the recoil is almost the same.

J E CUSTOM

 

[truck driver]

Sorry to here about your bad luck Actually I have always been a stickler for safety. I always took my 10hr break when it came even when the dispatcher wanted me to keep going. When I owned my own truck it always passed DOT inspections and when It need fixed I saw to it that it got fixed.

 

[Clark]

1) The threshold of recoil pain in a rifle I have given some thought:

Given:
The rifle weighs 10 pounds.
The bullet weighs 250 gr
The powder weighs 75 gr.
The muzzle velocity is 2500 fps
The gas velocity = 1.5 projectile velocity
The untrimmed large recoil pad is 9 sq inches
The recoil pad stiffness is 100 pounds/ 0.2"
The loss of Navcom material in Limbsaver recoil pad 75%
The threshold of pain is ~10 kg/cm2

Goal:
Calculate if it will hurt.

Calculation:
projectile momentum = mv = [[250 gr] / gravity ]][2500 fps] = 250 gr / 7000 gr/lb / 32.2 ft/sec2 [ 2500 fps] = 2.77 slug ft/sec
gas velocity = 1.5 projectile velocity = 1.5 2500 fps = 3750 fps
gas momentum = 75 gr / gravity 3750 fps = 1.25 slug ft/sec
Total forward momentum = bullet mv + gas mv = 2.77 + 1.25 = 4.02 slug ft /sec
rifle momentum = bullet + gas momentum = 4.02 slug ft /sec
rifle velocity = rifle momentum/ rifle mass = 4.02 / 10 pounds/ gravity = 4.02 / [10 / 32.2] = 12.9 fps
Rifle energy = [1/2] [m] [v][ v] = [.5] [[10] / [gravity]] [12.9] [12.9] = .5 [10 /32.2] 12.9 12.9 = 26 foot pounds
Energy not absorbed by recoil pad = rifle energy [1 - pad loss] = 26 fp [ 1 - 75%] = 6.5 foot pounds
The recoil pad stiffness is 100 pounds/ 0.2" = 100 lb / 0.0166 ft = 783 lb /.13 ft =
783 pounds compressed, 0 pounds relaxed, averages 391 pounds.
[391 pounds] [.13 ft] = 6.5 foot pounds
783 lb peak force / 9 sq in = 87 psi
The threshold of pain is ~10 kg/cm2 = 142 psi
87 psi peak pressure of recoil pad on skin / 142 psi threshold of pain = 62% of the threshold of pain

Will it half hurt?
No, because the whole shoulder moves, while 783 pounds of force may have been available to a brass statue shoulder, it was not realized. Only part of the energy goes into the recoil pad, unless the shooter is backed up against a tree.


------------------------------------------

More thought

The threshold of pain is ~ 20 psi on skin.
Some ways to keep recoil from reaching that level:
1) Lighter and slower projectile and gas
2) Heavier rifle
3) larger contact area on shoulder
4) compliant contact with shoulder to give uniform pressure over shoulder shape
5) spread the impact over time:
..a) recoil pad compresses
..b) parabolic taper hydraulic shock absorber
..c) separate recoiling mass delay line
.......1) semi auto mechanism bolt and carrier
.......2) Mercury starts in forward position and moves back in recoil.

 

[dstancu]

Back to physics: the law of conservation of energy states that "the total energy of an isolated system remains constant—it is said to be conserved over time. Energy can neither be created nor destroyed; rather, it transforms from one form to another."
The recoil energy is mostly kinetic energy. That means, it involves a dynamic action, not a static one. That kinetic energy cannot be destroyed, it will have to transform into another type of energy (potential energy that can take the shape of gravitational, elastic, or electric), or be transferred to other objects.
A rifle's recoil will:
1. partially transform in elastic potential energy in the buttstock and especially in the recoil pad. Thus, a well designed recoil pad can take quite an amount of energy (similar with the crumbling/elastic front and rear of modern vehicles)
2. partially transform in gravitational energy of the whole rifle which is moved to a new position (the heavier the rifle tho more is absorbed)
3. partially transferred to shooter's shoulder (an external system)
Simply put, the more goes in 1. and 2., the less gets to 3. (shoulder)
Now, what caused the discomfort on shooter's shoulder is more than just sheer amount of transferred energy. These are some of the main factors:
1. the total amount of kinetic energy transferred to the shoulder (less is better)
2. transfer surface (more is better) - here a recoil pad that dynamically molds into the shape of the shoulder for a fraction of a second, just enough to avoid painful high pressure impact zones
3. dynamic character of the impact - a rigid buttplate will transfer almost all of its kinetic energy in a fast, violent manner to the shoulder (like the swinging metal balls in Newton's cradle).
In real life, my own experience using the relatively simple LimbSaver recoil pad was very positive: I have them on two of my rifles chambered in .300 Win Mag and they made a world of difference. Especially for the lighter one (only 6 LB), which kicks like an angry mule... The effect on bullet's point of impact was an overall slight improvement (I was shooting well also before, at the cost of a blue shoulder after a day at the range), which I will attribute mainly to the better contact with my body during the recoil. No more crushed deltoid muscle and bruised skin...

 

[dig]

I have had two limb saver pads literally deform permanatly. They like melted in the heat of the truck and one in the garage. Granted it's hot in AZ but this is unacceptable. These pads are highly temp sensitive. A brick in freezing weather and jelly in the heat.

 

[FEENIX]

I have done lots of testing for muzzle brakes and recoil reducing devices and in the process did some comparison of different recoil pads.

all a recoil pad does is to distribute the recoil over a large area. all of the different types of
recoil pads only reduced actual recoil from 1 to two foot pounds. 70 % recoil reduction is impossible
for all but the very best muzzle brake.

On my web site I have all of the different recoil devices and there actual performance that may help to
understand the difference in these devices.

www.jecustom.com - FAQ's

J E CUSTOM

lightbulbJerry, as always, you keep it simple and NOT complicate things unnecessarily.lightbulb