Controlling Shotgun Recoil
The recoil reduction industry is a huge one. In fact, it is very hard to read a manufacturer's catalog, harder yet to read a magazine article, and virtually impossible to find ad-copy that does not promise it.
"Managed recoil loads" are available from many of the top shotshell manufacturers. Powders, wads, ports, pads, vests, forcing cones, mercury inserts, dead mules, over-boring, etc., etc., all promise to make shotgunning more comfortable. Does any of it matter? Well, let's look at a few of the popular recoil reducing methods.
Confusing the issue with common sense, the first stop is physics. Shotgun weight affects recoil on approximately a "one-to-one" ratio. Add 10% to a specific shotgun's weight, it kicks about 10% less. Lighten our shotgun by about 10%; it kicks about 10% more. That's all there is to it.
Muzzle velocity and ejecta (wad, shot, etc.) both affect recoil approximating a "two-to-one" ratio. Bump up the muzzle velocity by 10%, recoil increases by 20%. Increase our payload by 10%, again the free recoil goes up about 20%. That also, is about as simple as it gets. There are all kinds of ballistic programs that will give you a number to go along with it, if you need it, but that's about all there is from a "free recoil" standpoint. The matter of "felt" recoil is subjective, and most anything can be claimed in that department--and has been.
I. Wads Reduce Recoil
Cheap plastic resin wads are supposed to do all sorts of wondrous things, including sometimes reducing "felt" recoil. According to my shoulder, forget it. A lighter wad reduces "ejecta" mass, and will reduce free recoil, but not substantially. The "Windjammer" wads were supposed to reduce recoil, and often they did. In this case, it was because they often leaked like a sieve and reduced muzzle velocity. A few enterprising folks actually chronographed their loads, and the original "Windjammer" was replaced by the "Windjammer II." No longer did it seal so poorly, and no longer was it a "soft shooting wad." Forget the wad nonsense.
II. Hard Shot Reduces Recoil
This one is actually true, to a small degree. Most reloading tools (like my MEC 9000G units) drop shot by volume, not by weight. Hard ("magnum") shot has more antimony in it than chilled shot, and antimony weighs less than lead. So, yes, by a tiny amount a given MEC bushing dropping a high-antimony, extra-hard shot charge will produce a shell that produces less recoil than a soft ("chilled") shot charge dropped by the same bushing, if loaded to the same velocity. Unfortunately, it's not enough difference to notice.
III. Porting reduces recoil
This one has little basis, as there is so little gas pressure left in 12,000 PSI MAP (SAAMI maximum pressure) loads by the time the gas hits the ports that it can't do much of anything. The recoil reduction is minimal. Perhaps even sillier are ported choke tubes, which have even less pressure to work with. Drill enough holes in a perfectly good barrel, you will actually increase free recoil by a tiny amount, as you gun weighs a bit less.
Super-large extended choke tubes can also weigh a lot more than factory flush-mount tubes, and if they weigh enough they will reduce free recoil by our "one-to-one" ratio. Is it time to bring back the Cutts Compensator so we can all go deaf together? Porting as a significant recoil reduction method is just full of holes.
IV. Powder Type Reduces Recoil
This is another abused term. Slower burning powders are supposed to give us more of a "push" than a shove. Unfortunately, most of the slower burning powders require higher powder charge weights, a component of free recoil, and can actually increase recoil.
V. Mercury and Mechanical Recoil Reducers
These cylindrical devices are usually implanted in the butt stock of a shotgun, inserted into the empty chamber of a double, or screwed onto the end of the magazine tube of a repeater. Theoretically, they use mercury or a moveable mechanical weight that is supposed to attenuate felt recoil by spreading it out over a longer period of time. The claim is that the mercury (or mechanical weight) moves forward in the tube as the gun moves backward in recoil, thus "borrowing" some of the recoil energy and lowering the maximum amplitude of the kick. The weight returns to its start position, redepositing the borrowed energy, after the stock stops moving backward.
According to my shoulder, these devices seem to reduce recoil no more than adding weight in any other manner. (Adding weight, of course, does reduce recoil.) Dead Mules don't kick, perhaps, but they can nibble at your wallet. The mercury recoil reducers do add a humorous gurgling sound not available in stock factory shotguns. If mounted in the buttstock they also move the gun's point of balance back. This may be fine if the gun started out muzzle heavy, as many pumps and autos do, but is not so hot if the stock gun balanced properly.
VI. Stock Fit
There is no question in my young military mind that good stock fit can reduce felt recoil. It is, in fact, one of the most important factors in how we perceive recoil. A slap on the shoulder is far better than a slap on your schnoz, so (within reason) longer stocks may have less apparent recoil than shorter stocks. The comb must position your eye properly over the barrel rib without hitting you in the cheek on recoil. The butt plate should be sufficiently generous in surface area to spread the recoil over a large shoulder contact area.
Take from my own personal stupidity of shooting guns that didn't fit far too often. The eventual result was oral surgery to remove scar tissue from inside my right cheek. Bleeding over a stock is a venture without much future in it. Let my pain be your gain.
VII. Recoil Pads
The word "attenuate" is rarely used, except when describing recoil pads. Recoil pads do soak up recoil, and reduce the velocity of the recoil pulse as well in a meaningful way.
The best recoil pads on the market are the Kick-Eez and the Limbsaver. The choice between the two normally hinges on whether I seek to add weight to the butt of a shotgun to improve its balance. If I want a touch of extra weight, the solid and relatively heavy Kick-Eez pads get the call. If not, the lighter Limbsaver gets the nod. Both do a substantial and meaningful job of addressing felt recoil.
VIII. Action Type
Nothing kicks harder than a fixed breech gun and without question gas semi-auto guns have far less felt recoil than other action types. They achieve this by breaking up the recoil pulse into sections (the same recoil, but at lower level over a longer period of time), as beautifully described by Bob Brister is his book Shotgunning, The Art and the Science.
To sum up, it is impossible to get away from muzzle velocity, payload, and gun weight as basic components of free recoil, because they are. Mercury recoil reducers add weight to the gun, but little else. Quality recoil pads make high-volume shooting more fun, as do gas-operated semi-autos. Most other recoil "fixes" have comparatively little value.
The effects of recoil are cumulative, and you might not discover the difference until you've shot a case of shells. Then the difference between feeling essentially normal, or feeling like you've been pounded into the ground like a tent stake, is not that hard to discern.
Copyright 2006 by Randy Wakeman. All rights reserved.