rifle recoil

Understanding Rifle Recoil

In Bugle, Gear 101, The Hunt by Wayne van ZwollLeave a Comment

Recoil is a given. How much you get and how you deal with it can make a difference on your hunt!

Bullet launch is a violent event. The sudden expansion of powder gas that boots a snug-fitting bullet from zero to 3,000 feet per second (2,045 mph) moves the rifle, too. You’re the brake. You absorb the recoil.

No matter how big or tough you think you are, you will react to punishing recoil. Flinching moves your rifle before bullet release, so it affects point of impact.

Sir Isaac Newton described recoil when he determined that for every action there’s an equal and opposite reaction. You can pencil out recoil’s kinetic energy using this formula: KE = MV2 / GC, where M is the rifle’s mass and V its velocity. GC is the gravitational constant.

To get rifle velocity, we must crunch some numbers.

The formula: WV = bullet weight / 7000 x bullet velocity + powder weight / 7000 x powder gas velocity. Art Alphin’s A-Square manual suggests using 5,200 fps as an average gas velocity. The “7000” denominators simply convert grains to pounds.

Using these formulas, you’ll find a 180-grain bullet fired at 3,000 fps from an 8½-pound rifle in .300 Winchester delivers about 30.5 foot-pounds of recoil. A same-weight .30-06 dishes out roughly 22 foot-pounds. Hiking bullet velocity exacts a high price in recoil!

Rifles chambered for cigar-size British Express rounds originally loaded with cordite are commonly considered mellow in recoil—as if those heavy bullets shuffling off at bicycle speed are too well mannered to maul your shoulder. But they can still trigger a flinch. One .700 Nitro Express pushed me hard enough to force a step back while the barrels of the 17-pound double rose 45 degrees. Even the likes of the .416 Rigby and .470 N.E. can bump your clavicle hard enough to make you wince.

While case shape seems to affect recoil, sifting fact from speculation is difficult. In my experience, steeply tapered rounds like the .300 Holland are more civil than cartridges with sharp shoulders. No science behind that observation, just lots of shooting. The .378 Weatherby may carry a bullet only half as heavy as a 570-grain solid in the .500 N.E. But the .378 kicks savagely. A .45-70 round launching a 405-grain bullet at 1,800 fps from a Ruger Number One (not a load for your trap-door Springfield!) gives you about the same blow as a .338 Winchester Magnum hurling a 225-grain spitzer 2,800 fps, mathematically speaking. But a rifle in .338 can seem more punishing. The bullet exits faster, from a sharply bottle-necked case.

Rifle design definitely affects felt recoil, which is why one rifle can seem to baby you while another of the same weight, firing the same ammunition, kicks like an ostrich. The short breech sections of doubles put the muzzles closer to your face, and their off-center bullet launch pivots the rifle. True, they have twice the barrel steel, and velocities and breech pressures are low. But while a double’s slender forend and slick barrels help you point the rifle fast, they give your hand little purchase. Braking rifle movement with your forward hand is easiest with a pear-shaped forend that settles naturally in your partially closed palm. Checkering improves grip. The front swivel must be far enough forward to clear your hand. Rifles that kick very hard are best equipped with barrel-band swivels—though when you employ a tight sling for a shot, tension on the barrel affects bullet placement. An intelligent compromise is a swivel stud on the forend nose. Blaser’s R93 has this feature. Lex Webernick offers it on his Rifles, Inc. guns.

One of the most critical parts of a rifle stock as regards recoil is the comb. It should be as straight as the sights allow, so when the rifle lifts and backs up suddenly, the comb does not bang your nose. Roy Weatherby’s Mark V rifle has a forward-sloping comb that moves away from your face. In my view, this feature really does reduce felt recoil. Any comb with a gentle radius that tapers forward, and a top-line that recedes forward, should help you shoot better. Add a cheek-piece that supports your jowl but does not force you to cant your head, and you’ll feel less bite. A long, checkered grip that encourages full-hand contact also helps tame the rifle, because it affords you more control. Your right hand can absorb some of the kick that gets by your left, leaving your shoulder to deal with much-reduced impact. The more you can spread recoil, the less you’ll feel it.

Distribute the blow at the butt with a gently concave recoil pad. The curved steel butts on 19th-century firearms designed to be fired off the upper arm don’t make sense on modern rifles with stiff recoil. Contemporary steel plates and skeleton and Neidner-style custom plates look good but aren’t as kind to you as soft materials. A rubber pad (or similar synthetic) is also less apt than a hard plate to slip out of place as you fire and cycle the action. It will grab the ground if you lean your rifle against a tree. A butt pad protects the stock better from water damage, as it can be secured with adhesive that seals the wood. And it keeps the end grain farther off snow and wet grass. When I was young, rubber pads got hard with age, and if you stored the rifle on its butt, the pad would retain the bulge. It’s still not a good idea to leave the rifle’s weight on a recoil pad (I store my rifles muzzle-down), but pad materials now last much longer and absorb recoil better. Among the most attractive: Old English by Pachmayr. The best at dampening kick: Kick-Eez.

Want more recoil reduction? Consider a muzzle brake, which trims recoil by mitigating jet effect. It bleeds gas pressure through ports instead of letting it erupt as the bullet base clears the muzzle. A brake also provides opposing surfaces fore and aft of each vent for the gas to push against. So not all the thrust goes rearward. A brake can make a .30-06 feel like a .243. The drawback is noise. A brake can increase muzzle blast to the point that even in the field you’ll want ear protection. If your guide sees a brake on your rifle, he might (justifiably) insist before the hunt that you never fire until he is behind you. A brake can generate a tornado of dust or snow if you fire prone. Brakes used to be as homely as the Poly Chokes on shotgun barrels in the days of black-and-white TV. But brakes have become streamlined. One of the best comes from Rifles, Inc. “The .300 Winchester is my most popular chambering,” says Lex Webernick. “But without a brake it can be violent in a 6-pound rifle.” Lex’s brakes are barrel-diameter and as quiet as any on the market.

Installing a brake increases the length of your barrel a couple of inches. Velocity is not affected because the bullet doesn’t contact the brake. Accuracy shouldn’t change; but you’re smart to check. You may want to remove a brake for a hunt, where recoil is almost a non-issue. (A six-point bull in your scope can make you forget that rifle’s kick!) And cold-weather clothes mitigate recoil that can bruise you through a flannel shirt on the bench in September. A steel cap threaded onto the barrel in place of a brake spares you the blast. One caveat: Not all barrels shoot to the same point of impact when you remove or install a brake. Check before you hunt!

Another option is a recoil-damping device inside the butt-stock. Blaser offers these in its Safari R93s. Recently I fired a couple of boxes of .375 ammo through a Blaser so equipped. It kicked about like a .30-06. Some of these devices contain mercury to hike inertia. Weatherby’s new Vanguard Axiom rifle wears a Knoxx stock. The two-piece grip features an angled plate that mates with another plate. A stout spring keeps the pair engaged until firing. Recoil pushes the top plate over the bottom plate. The spring quickly returns them to their original positions. Weatherby’s claim: “up to 95 percent recoil reduction.” Knoxx stocks on 12-gauge slug guns I’ve fired substantially softened the kick.

The simplest way to keep from getting smacked in the molars (see video below) by your stock or bruised purple on your pec by a butt-pad is to settle on a cartridge that doesn’t look or behave like an artillery round. If you need more than a .270 to kill an elk, you’re hunting animals much bigger and tougher than any I’ve encountered in 35 years on the hill. While magnums have their place, the .30-06 is almost always enough. Few hunters can shoot accurately under field conditions farther than an ’06 will drop elk. Deadly shooting follows disciplined practice, and you won’t practice if your rifle beats you up (or if a box of ammo costs more than a week’s groceries).

Boosting rifle weight reduces both actual and felt recoil. Still, you must carry your rifle to where elk live; a heavy rifle slows you down. A heavy scope can tear itself free of rifles that kick hard. Once when zeroing a .416 Rigby, I failed to notice the scope come loose. The rings were secured by clamp screws on bases with terminal lips. When I triggered the last round in a long series, the scope flew off the rifle, clobbered me between the eyes, then somersaulted over my head. Each shot had bumped the rings harder against their stops. At the final shot, the rings had bounced off the ledges violently enough to clear the bases.

Shooting position and form affect felt recoil. Offhand is not a steady position; for that reason, it spares you the full force of recoil. Your body is free to move under the jolt. Shoulder and back yield to the blow. Offhand is the position of choice for testing hard-kicking rifles. The people at Rigby fire their powerful doubles over a “standing rest” that affords the stability of a bench but lets the shooter’s torso move with the rifle. Any unsupported offhand position, however, is singularly unforgiving of a flinch!

The lower your position, the less “give” it has during recoil. Prone you’re not flexible at all. Your body’s weight holds you all but immobile; shoulder and face stop the rifle. If, like me, you have little meat on your clavicle, stiff recoil makes prone shooting as much fun as root canals. Sitting and kneeling let your body rock without falling out of position.

Incidentally, the scarring on my brow did not result from too much shooting with powerful rifles, but from shooting with rifles whose scopes were placed too far to the rear. To avoid such injury, scoot your scope well forward. Remember that on the mountain you may have to fire prone or sitting or uphill, positions that put the ocular ring closer to your eye!

Offhand and kneeling, you’re smart to keep your head erect and eyes straight ahead in the sight, so as to get the clearest sight picture. But we shooters with long necks don’t get full shoulder contact this way, and the toe of the stock concentrates recoil. The bad news: we just have to suck it up. Moving the rifle down on your shoulder ruins your position.

Muzzle blast—concussion and noise—and the rifle’s sudden jump can affect you in much the same way recoil affects you. You can’t do much about the suddenness of this violence, but you can reduce it as you limit recoil: by using a round that recoils civilly in a rifle of reasonable weight without a brake.

You won’t easily practice your way out of a flinch with the rifle that caused it. Unwilling to shoot elk with anything but a lightweight .338 UltraMag? Fight the flinch by practicing with a .22 rifle.

Recoil is a predictable and measurable result of firing. Choosing a rifle and a cartridge, you determine how much recoil you’ll get. If it’s enough to trigger a flinch, it is too much!