Muzzle Brakes

Spec Ops Shooting

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I did not fully appreciate the effectiveness of a muzzle brake until repeatedly firing .50-caliber rifles. The first time I fired a .50, I was tensed up for a real jaw-shaking, something worse than a .458 Winchester Magnum elephant gun. Instead of roaring like a lion, however, that .50 purred like a kitten. The recoil was not even as strong as a .300 Winchester Magnum.

Part of the effect was attributable to the gun's weight—more than 30 pounds—though equally it resulted from an effective muzzle brake. Muzzle brakes come in an assortment of clamshell and wedge shapes or in the form of vents machined near the muzzle, but all deflect gases to "pull" a rifle forward, off the shooter's shoulder. Efficiency varies, but on average there's probably a 30 percent reduction in felt recoil. That's the good news.

The bad news is that by deflecting the muzzle blast, a brake also increases the rifle's report and generates quite a plume of dust. At Gunsite, braked rifles proved so loud (even on a .300 Winchester Magnum) that we could not position students on adjacent firing points to a brake-equipped shooter. Dr. William Kramer's Ball State University study of muzzle blasts found that adding a muzzle brake increases a rifle's acoustic energy 10 times. Further, he learned that a muzzle brake's "initial sound"

shifts the blast to a lower 1,600 Hz pitch, a frequency especially uncomfortable for humans.

In combat a muzzle brake will increase a sniper's sound and visual signature, though these can be lessened by selecting a suitable Final Firing Position (FFP) and either wetting the ground or laying a cloth beneath the muzzle—but that doesn't always work, either. During a military firing demonstration, an instructor laid a poncho before the muzzle of Dr. Barry Kaplan, a friend and fellow Special Forces combat vet. When Kaplan fired his .50, that poncho disintegrated into a hundred pieces, so powerful was that muzzle blast. If I were designing a muzzle brake, I'd vent most of the gas upward. Some suppressors take this a step further and all but eliminate muzzle signature, even on heavy ,50s.

Another kind of brake worth addressing is the Browning BOSS (Ballistic Optimizing Shooting System) which incorporates both a muzzle brake and a harmonic barrel tuner. Actually, the muzzle brake aspect—angled holes reminiscent of Magna-Porting—was an afterthought because the BOSS is really all about harmonic tuning. This muzzle brake— especially on low- and medium-powered cartridges such as the .223, .308, and 30.06— proved unnecessary and only made these rifles acoustically uncomfortable to shoot. To address this, Browning fielded a second BOSS version, the CR (Conventional Recoil), which lacks the muzzle brake.

The connection between barrel harmonics and accuracy has long been known though not well understood. In 1915, British sniping officer H. Hesketh-Prichard warned his men not to place bayonets on their sniping rifles "because the extra weight slows down the vibration" and would thereby "throw your shot 18 inches high at 200 yards' range." As explained concerning free-floating, upon firing a barrel vibrates like a tuning fork, which affects the bullet as it transits and exits the muzzle. Browning engineer Clyde Rose noticed that he could improve the accuracy of mediocre rifles by cutting off a bit of the barrel—and

Browning Boss

The Browning BOSS harmonic tuner, without muzzle brake (above) and with the brake (below).

realized that, actually, he was "tuning" the harmonics. What if, he thought, you attached a highly adjustable barrel extender to a muzzle— you'd just crank it back and forth until you found the optimal harmonic length. Eureka!

Rose's device, the BOSS, offers micrometerlike adjustments, with 10 settings on each of 10 rotations—100 distinct barrel lengths to fine-tune harmonics. In essence, this is the opposite of what a handloader does: instead of tuning the load to the rifle, you're tuning the rifle barrel to the load. I tested the BOSS extensively and found that it worked superbly—-yet it has not taken off like I thought it would. The ear-shattering reputation of the original muzzle brake version turned away some shooters, and it may be a bit too complex for others. However, I can assure you, the BOSS works.

Auxiliary Open Sights

Although the U.S. Army's M24 Sniper Weapon System includes the excellent Redfield/Palma International iron sight with 1/4 MOA windage and elevation adjustments, my personal inclination is to outfit a sniper rifle with an optical sight only. It's not that the Palma sight won't work or it's inaccurate; it's just that there's so much to learn and practice in mastering a rifle scope that I'd much rather have students not divert time from such critical training.

Some Special Ops friends would argue that optical sights can fail for a host of reasons, and they're right. But such failures are rare, and, face it, if your scope breaks you aren't going to continue your sniping mission. Either the mission will abort or you'll pick up an M16 and join your infantry brethren until another sniper rifle's available.

A police sniper, of course, would never attempt a critical shot after his scope was broken, both because of liability and the normal proximity of other police snipers who can take over the mission.

Still, I think it's just fine to have a simple fixed sight, like that on the Steyr SSG, and recognize that it's for emergency use in self-defense, not for sniping.

The Bolt Action

All things being equal, a bolt action is the most accurate action one can have on a rifle. Here's why.

In the early 1960s, I pooled money with my boyhood squirrel-hunting companions Joe Remarke and Vic Evaschuk to buy a single-shot, bolt-action .22 rifle. Our arrangement was that one of us stalked forward until he had a shot and then turned the rifle over to another. If you missed, it could be an hour before it was your turn again,

1960 Remington Bolt Action

A simple fixed auxiliary sight, such as this one on a Steyr SSG, is an essential backup in case your scope's inoperable.

and any bushy-tail you saw during the interim laughed at your predicament. No unarmed boy likes being the butt of squirrel humor.

Seriously, though, shooting in such disciplined circumstances meant each shot counted and resulted in one squirrel bagged for each shot fired. It was phenomenal shooting.

A year or two later, when we all had parttime jobs, we purchased ,22 automatics—Joe got a Ruger, Vic got a Browning, and I a Remington—and our shooting went to hell. We'd lost the mental focus required for one-shot hunting.

There's something psychological about bolting a rifle—a kind of finality, a bonding of spirit with task that isn't present with any other rifle action.

Bolting a rifle also results in seating a cartridge in a chamber more firmly and consistently than any other action. Think about how it feels when the locking lugs engage and your palm presses the bolt handle downward. That action doesn't just "move" into place, nor is it pushed there by spring action. No, as the bolt rotates downward, the action tenses and locks snugly. Provided the action is true and straight, this cannot help but lead to consistency, and remember that accuracy equals consistency and vice versa.

When it comes to the bolt being true and straight, this is one of the first areas for tuning. Quality bolt guns should have locking lugs lapped so they bear perfectly against mating surfaces. All lugs should be uniformly in contact and the facing surfaces polished smooth. The bolt face is perfectly flat so that a seated cartridge is not wedged or twisted out of line in the chamber when its base rests against the bolt.

Behind that bolt face is the firing pin, and its performance, too, impacts directly on rifle accuracy. Lock time, which is the time that passes between your finger releasing the sear— "breaking the shot"—and the firing pin striking the primer, is a reflection of rifle quality7. A fast lock time is needed so the rifle has no time to move between the instant you pull the trigger and a split-second later when it actually fires. Acceptable lock time results from bolt design and using proper lubricants. Lock times may vary from .0022 to .0057 of a second. The quality sniper rifles cited here have acceptable lock times.

There can be no question that America's most popular sniper rifle action is the Remington 700. In Vietnam, both Army and Marine snipers used heavy-barreled Remington 700s, a practice that continues to this day.

The USMC M40A3 represents the 700's latest evolution. Unlike its Vietnam grandfather, however, the newer version is hand-built by talented Marine technicians at Quantico's Precision Weapons Facility. Here they incorporate a Schneider match-grade stainless heavy barrel along with an epoxy-bedded

Picatinny Rail System Savage Rifles


McMillan A-4 stock and Picatinny rail, which can accommodate day or night optics. The final product is 2 pounds heavier than the earlier version, with most rifles shooting better than 1 MOA.

The Army's M24 Sniper Weapon System, also based on the Remington 700, may look similar but there are many differences. To allow conversion to .300 Winchester Magnum, the Army rifle uses a long action even though most rifles are chambered for .308 (7.62x51mm). These guns, developed by Remington's John Rogers, incorporate an aluminum bedding block and an H.S. Precision stock adjustable for length. The NCOIC of the Army Sniper School, MSgt. Kurt Judson, says this rifle shoots so well that "it almost shoots itself." Remington is now marketing the M24 to police, either as a complete system or the rifle only. Recently Remington updated this rifle into the M24A2 configuration, which adds a rugged, detachable box magazine, oversize bolt knob, Picatinny rail, and optional suppressor, while also fitting it to a new adjustable stock.

Though both the Marine and Army rifles employ Harris bipods, and both systems use lOx fixed scopes with Bullet Drop Compensators (BDCs), the Army prefers the Leupold Mark 4 M3s while the Marines use the Unertl. In recent years, however, some Marine rifles have been topped by the AN/PVS-10 day/night scope as well as Leupolds.

Most U.S. police agencies I've instructed or worked with use Remington 700s—primarily

Harris Bipod Company

The USMC M40A3 uses the excellent McMillan A-3 adjustable stock, Harris bipod, and match-grade stainless barrel. Optics include this Unertl 10x, Leupold 10x, or sometimes the AN/PVS-10.

the company's own Model 700P (Police), although a few, like the Secret Service and U.S. Marshal's tactical team, have the more sophisticated Remington Model 40-XS tactical rifle. A standard Remington police rifle typically shoots about 1 MOA.

Many custom sniper rifle builders use the Remington 700 action—Robar, McMillan, AWC, H.S. Precision, and Brown Precision, to name a few. These rifles may resemble the "ordinary" 700, but they've been finely tuned for peak performance. Robbie Barrkman guarantees his SR-90 rifles to shoot 1/2 MOA when firing match-grade ammunition.

The only criticism I've encountered with Remington 700s concerns the extractor. Rumors abound that this thin, stamped metal blade is prone to failure, but despite owning a half-dozen 700s, shooting many others, and working with hundreds of police and military snipers, I have never encountered anyone who experienced such a failure. Still, just to ensure that this cannot happen, McMillan replaces the standard Remington bolt on its custom rifles with a Mausertype bolt featuring a large claw extractor.

Although Marine sniper legend Carlos Hathcock accumulated his 93 kills using a Winchester Model 70 bolt-acuon, very few police or military snipers use this rifle today. Winchester does not market a special police sniper rifle, but a related company, FNH, recently began building a variety of high-end sniper rifles that use the Model 70 action. The FN A3G and FN A4 Shooting Systems use McMillan adjustable stocks, with the latter version selected by the FBI for its SWAT teams.

Savage Arms has developed tactical versions of its well-established 110 action, called the Law Enforcement Series. I purchased one of their early rifles in .223 and found it an honest 3/4 MOA rifle, quite an achievement for a modestly priced gun. More recently Savage has incorporated a McMillan or my own Choate stock along with their superb AccuTrigger to field a rifle that's surprisingly accurate at a very reasonable price. Though I receive no royalties, I'm delighted at this gun's performance. It was

308 Awc Suppressor

AWC custom-builds this copy of the USMC M40A2.

M40a2 Pics

Along with a full line of custom rifles, Brown Precision produces this Tactical Elite rifle for police snipers.

Brown Tactical Elite

The FN A4 Shooting System, used by FBI snipers, incorporates a tuned Winchester 70 action and the same McMillan stock as the USMC's M40A3.

Snipers Winchester

Savage's police sniper rifle, the Model 10FPXPLEA, is acceptably accurate despite its moderate price

Savage 10fpxp LeaLighter Spring Accu Trigger
The Accuracy International police variant, the AWP, mounts a heavier barrel than the AW.
Winchester Model Firing Pin

A German police sniper team with a Mauser SR93 .300 Winchester Magnum rifle and (rear) Zeiss stabilized binoculars.

Navy Seals Sniper Winchester MagnumWinchester Model Firing Pin

pcrcent lighter than the steel pin it replaces— instantly improves lock time.

Mechanically, there are pros and cons when it comes to semiautos. On the plus side, there's an appreciable reduction of felt recoil due to the gas system and recoil springs. On the negative side, the gas system thrusts back the piston, operating rod, bolt carrier, and bolt, which suddenly shifts the center of balance rearward, then jerks it forward again, adding complexity to follow-through and recoil recovery. I think it takes a slightly different hold to control a semiauto as steadily as a bolt gun, a kind of "feel" you can only perfect through practice.

Refining these sniper versions of 7.62mm assault rifles requires all the modifications and close tolerances found in bolt guns, but with some additions. The trigger is replaced and all internal springs tuned or changed. Recoil springs are especially important since rounds must chamber with consistent pressure, just as your snugging down a bolt by hand causes consistent chambering. Further complicating accurizing is the fact that, due to the gas port and tube, many semiautos cannot be truly free-floated. The solution is to anchor anything that touches the barrel firmly so its harmonic vibrations at least are consistent.

Current Semiauto Sniper Rifles

America's Vietnam-era semiauto sniper rifle was based on the A414. Though much attention has been paid to the combat achievements of Remington 700s, M14-based sniper systems certainly have an equally impressive record.

In the open, flat expanses of the Mekong Delta, the U.S. Army's most accomplished Vietnam War sniper, Sgt. Adelbert F. Waldron III, exclusively used an XM21 System to account for a confirmed 113 enemy kills. The war's top Marine sniper—with 103 enemy KLA, 10 more than Carlos Hathcock—my longtime friend, Sgt. Chuck MaWhinney, often used an M14 with Starlight scope for night operations, during which he achieved more than 30 percent of his kills. One night Chuck used a PVS-2

Adelbert Waldron

Sgt. Adelbert F. Waldron III, the U.S. Army's top Vietnam sniper, takes aim with the XM21 with which he killed 113 enemy.

night scope on an M14 to pick off an entire file of North Vietnamese troops crossing a river, shooting 16 of them exacdy as renowned World War I rifleman Alvin York had done—back-to-jrom—so the approaching enemy could not appreciate the deadliness of his fire.

It was an updated version of the XM21 system—the M25—with which Delta Force sniper MSgt. Gary Gordon engaged untold numbers of assaulting Somalis in Mogadishu in October 1993, killing "an undetermined number of attackers until he depleted his ammunition," according to his posthumous Medal of Honor citation. His spotter, Sgt. 1st Class Randall Shugart, went down shooting beside his sniper team leader, firing his M4 carbine to the bloody end.

M14-based sniper systems are found today in both the Army and Marine Corps. The USMC version is a basic M14 upgraded by Corps precision gun builders with a match-grade barrel, McMillan stock, plus fine-tuning to become the

Usmc Mcmillan Dmr Stock

The U.S. Army's Designated Marksman Rifle in Iraq. This model has a resin-impregnated stock and Leupold Mark 4 M3 scope, identical to the M24 system's scope.

Designated Marksman Rifle (DMR). There's one DMR-armed rifleman per infantry platoon.

The Army's version can be found either as an M21 or M25 system, with the latter adding a stainless match-grade barrel and synthetic stock. The original M21 uses a dense, resin-impregnated wooden stock. The ART scopes on both models have been replaced, either by the Leupold Mark 4 or AN/PVS-10.

Springfield Armory continues to build a high-quality version of the M21 based on their Super Match Rifle. Using a Hart, Krieger, or Douglas match-grade barrel and a stock featuring an adjustable cheekpiece, this rifle is employed by police agencies and military Special Ops units worldwide.

Whether a military-built gun or Springfield Armory product, I believe the DMR/M21/M25 is an ideal spotter's weapon because ballisticaUy it matches the sniper's .308 bolt gun round;

Springfield Armory's M25 rifle uses match-grade components and an adjustable synthetic stock.

Mcmillan Stock For Tikka

The USMC Designated Marksman Rifle uses a McMillan synthetic stock and the same Leupold optic as Army sniper rifles.

adds a high-magazine capacity, rapid-fire capability to the team; and allows both shooters to share range and windage "dope." Further, I think it's just as suitable for police sniper teams as military ones.

That variety of semiauto 7.62mm sniper/ spotter rifles certainly includes the excellent SR-25, manufactured by Knight's Armament. Designed by the legendary Eugene Stoner, the company guarantees the 24-inch-barreled SR-25 for 1 MOA accuracy. In recent years several updated SR-25 versions have evolved, with the 20-inch-barreled Mk 11 Mod 0 rifle adopted in 2000 by the U.S. Navy SEALs. To achieve high accuracy with this shorter, free-floated barrel, company engineers had to improve or change the

Stoner Match

The U.S. Army's latest M14-based rifle incorporates a Picatinny rail and telescoping stock.

M14 Rifle BlueprintsStoner MatchSuper Match Interdiction Rifle
T h li S n i ]» li r ' s R i i- i. k 63
550 Sniper

The SIG SS6 550 Sniper is a match-grade, highly tuned .223/5.56mm rifle. It's used by a number of European police agencies and the Swiss army.

Mauser Super Match

This .300 Winchester Magnum semiauto from Arms Tech, the Super Match Interdiction Rifle, is built on the Browning BAR rifle action.

Tech Super Match Interdiction Rifle. Custom- McMillan A-2 stock. The resulting weapon, built in Phoenix, Arizona, it incorporates a with scope and bipod, weighs more than 13

highly modified Browning auto action, heavy pounds. This rifle saw combat action in match-grade 26-inch stainless barrel, and Somalia in 1993 and was well regarded by the

Seal Sniper Somalia 1993Browning Bar With Muzzle BreakSuper Match Interdiction RifleSuper Match Interdiction RifleSpectrum 2000 Suppressor Awcm92

This AWCM92 rifle is fitted with a Spectrum

2000 suppressor.

Factory-suppressed version of the AW rifle.

Factory-suppressed version of the AW rifle.

Rifle Terminal BallisticsSuper Match Interdiction RifleSuper Match Interdiction Rifle

some kind of trade-off, in this case significantly reduced ballistic performance. Blundy put: you will not be able to shoot as accurately» nor with nearly the terminal ballistics, nor as far as with a normal sniper rifle.

To start with, even if you're firing full-power ammunition—not subsonic—the combination of a shorter barrel and suppressor will degrade accuracy and reduce the bullet's kinetic energy. The marvelous SSG, for instance, will lose about 200 fps velocity due to the shortened barrel, with a resulting energy decline of 15 percent, or 373 foot-pounds. This slower initial velocity will cause the bullet to plunge earlier and more drastically than otherwise, changing your ballistic tables and knocking any Bullet Drop Compensator (BDC) out of synch with the bullet's true trajectory. For instance, a Federal .308 Match 168-grain fired through a 16.5-inch barrel will hit a target 10 inches lower at 500 yards than will the same bullet fired through a full-size SSG.

Equally important but less objectively measurable are the effects on accuracy of firing a match-grade round through a suppressor. Installing a suppressor adds variables to your rifle: the way in which the bullet travels down the suppressor, as contrasted with how it travels down the barrel; internal ballistic issues on bullet acceleration and stability from a short barrel; and changes in how the suppressor handles blast/gas as carbon and heat transform it internally the more you shoot it. Having not tested these factors myself, I'm hesitant to cite an acceptable standard except to say that a suppressed sniper rifle that fires 1 MOA or better would be a most impressive weapon.

But what about firing subsonic ammo? It should be obvious that reducing a 168-grain bullet's velocity from 2,600 fps to 1,050 fps will degrade the round's trajectory, while the slower speed dramatically reduces the round's muzzle energy from 2,521 foot-pounds to a mere 390 foot-pounds.

To visualize what this means, realize that this terminal effect is similar to that of a .45

automatic pistol! That's right, your 168-grain subsonic bullet's trajectory, energy, and penetration are comparable to handgun performance. This means your maximum effective range while firing subsonic ammo is probably 100 yards for head shots, with energy now below 300 foot-pounds. At that distance, you will not be able to penetrate an opponent's body armor.

"Well," you tell yourself, "then I'll just fire full-velocity ammo and accept that there will be a supersonic crack." That's not really a solution either. Lacking subsonic 5.56mm ammo, Medal of Honor recipient Franklin Miller and I experimented with a suppressed M16 in SOG because we'd been told that despite this crack, the suppressor would still confuse the enemy about a firer's location. The only place that proved true was behind the weapon; from anywhere within 45 degrees of the shooter's front, that high-velocity crack told us his approximate location. Neither of us ever carried it on a mission.

A 1992 Finnish government study scientifically confirmed our experiment. Firing full-velocity loads at 128 meters from a .308's muzzle, it was found that "suppressed and unsuppressed [decibel] levels in front of the rifle were rather close to each other," although "to the side the sound levels were significantly reduced." I think had we and the Finns continued this testing at greater range—over 300 yards, perhaps—we'd have found it more difficult to discern the shooter's location.

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  • alastair
    How much reduction with clamshell muzzle brake?
    9 years ago
  • filmon
    Do snipers use muzzle breaks?
    8 years ago
  • ruta
    HAS anyone shot elephants with a 300 winchester magnum?
    8 years ago
  • robert
    What effect does a suppressor have on performance for tikka .300?
    8 years ago
    Does the USMC put muzzle brakes on the m40a3?
    5 years ago
  • ronja
    Do snipers use muzzle brake?
    5 years ago
  • leah
    Are there any other ballistic optimizing systems other than the boss?
    3 years ago
    How long is barrel on browning with muzzle brake?
    3 years ago
  • lauryn
    Do snipers use muzzle brakes?
    3 years ago
  • mungo
    How snipers eliminate the gun muzzle?
    3 years ago

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