In the field and on the firing line, more and more of today’s marksmen are abandoning the crank handles.
When it comes to the ultimate in accuracy, most people turn to bolt-action rifles. Except for service and action rifle competitions, this is true for almost all other types of target shooting from smallbore to bench rest to 1,000-yard matches. It is also true for most hunting that requires a particularly high level of accuracy, be it long-range varmint hunting, mountain sheep hunting or bean-field deer hunting. Even the world of police and military sniping is dominated by bolt-action rifles.
The innovative M1913 Picatinny rail base, as seen on Springfield Armory’s M25 White Feather, is commonly used today to mount a variety of optics on accurate semi-automatic rifles.
However, thanks largely to efforts by the military shooting community to field extremely accurate semi-automatic service rifles, we have entered an era where the semi-automatic rifle has become so accurate that it is competing solidly with, and often beating, bolt-actions at their own game. An excellent example demonstrating this newfound dominance occurred at the 2007 National Matches.
The NRA High Power National Match is shot with a centerfire rifle with metallic sights and a magazine capable of holding no fewer than five rounds. The course of fire requires shooting at 200, 300 and 600 yards, and includes timed and rapid fire with a reload in two of the phases. Through its long existence, this course of fire has been dominated by bolt-action match rifles. The 2007 winner, Carl Bernosky, had previously won this honor seven times since 1977, all shooting with a classic bolt-action match rifle. In 2007 he won it again, but this time with an AR-15 match rifle. To show this was not just a lucky fluke, using the same semi-automatic rifle at the 2007 National Matches, Bernosky won the overall High Power Rifle Championship, took titles as the NRA Match Rifle Champion and Civilian Champion, and top honors in the Vandenburg Cup Match, the Nevada Trophy Match, the McCann Trophy Match, the Member’s Trophy Match, the Scott Trophy Match, the Erdman Trophy Match and the Marine Gunner D.I. Boyd II Memorial Trophy Match. It is safe to say his semi-automatic match rifle was highly accurate and more than competitive.
Adjustable cheekpieces are increasingly common as standard equipment on semi-
automatic rifles designed for long-range accuracy, like the M25. (top)
Bipods offer an extra degree of stability while shooting prone; all the more important when quick follow-up shots are required. (lower)
The story of highly accurate semi-automatic rifles pretty much started with the venerable M1 Garand. Fans
of the M1903 Springfield were certain the M1 Garand could never shoot as accurately as their beloved bolt action—nor would it be as reliable. The Marine commander at Guadalcanal even turned down the offer of a large quantity of M1 Garand rifles from the Army prior to their invasion. Later those Marines would learn the M1 was highly reliable, arguably more durable than the M1903 and surprisingly had a higher level of practical accuracy. The latter was primarily because of the M1’s vastly superior sights. Indeed, the M1 Garand could shoot so accurately that before World War II ended, it was fielded in the form of the M1C and M1D sniper rifles.
After World War II and Korea, the military service shooting teams and arsenals began working over the M1 Garand to improve its accuracy. The result was the highly accurate National Match (NM) M1. It was not long before the M1 dominated the National Service Rifle Championships. I still have my late father’s 1960 vintage NM M1 and it will still shoot 2 MOA or better with match ammunition. As the match M1 armorers learned their trade better, it was not uncommon for match M1s to be able to consistently shoot 1 MOA.
In the ’60s, the Army Marksmanship Training Unit (MTU) started to apply similar accurizing procedures to the M14 rifle, the M1’s replacement. The M14 was an improved M1 to start with and service-issue M14s typically shot more accurately than their M1 counterparts. This was primarily because the M14 got rid of the problematic, overly long operating rod/piston system of the M1 and 7.62 mm service ammunition was more accurate than .30-06 M2 ball ammunition.
These efforts led to the development of the National Match M14, as well as match versions of the civilian M1A equivalent. Initially the match M14 and M1A rifles were only marginally more accurate than the top match M1 Garands, but with the advent of improved heavy barrels, synthetic stocks and other developments, eventually the level of accuracy achieved with these rifles approached or achieved 1⁄2 MOA.
These super accurate M14 and M1A rifles dominated service rifle competition for decades, upsetting the records achieved by the M1 Garand. Today Springfield Armory offers its M1A-based M25 White Feather Sniper Rifle with a guarantee of 1⁄2 MOA performance. I own one of these gems and it will indeed routinely shoot 1⁄2 MOA with Hornady .308 Win. 110-grain TAP and Black Hills 168-grain .308 Match ammunition. However, the M14/M1A family has the justified reputation of requiring the frequent attention of a match armorer to maintain that level of performance.
The enhanced palm swell of the M25 aids in a relaxed grip, while texturing adds the extra purchase needed for foul weather use.
Eventually the commander of the Army MTU decided it was time to investigate the use of the M16 for service rifle competition. The adoption of the M16A2, with its 1-in-7-inch twist rifling that can stabilize much heavier bullets than the original M16, was an important factor in getting the gun to compete successfully at 600 yards.
When fired with match-grade ammunition, the basic M16 is probably the most accurate standard service rifle the U. S. has ever issued. Designed by Eugene Stoner, the M16 uses a direct gas impingement operating system. This system has tremendous advantages over any of the other gas-piston systems with regard to achieving high accuracy. Basically, the gas behind the bullet is tapped well down the barrel through a hole in the barrel. It enters a tube that transports that gas back to the rifle’s receiver where it impacts an extension of the bolt carrier. When the bolt carrier is pushed to the rear, it unlocks and pulls the bolt rearward, initiating bolt reciprication.
With this system there is no operating rod, piston or gas cylinder hanging onto the rifle, rattling around, moving and imparting vibrations while the bullet travels down the barrel. It is also relatively easy to free float the M16’s barrel to take advantage of this situation, something that is nearly impossible with most other gas-operated semi-automatics. Even better, when properly set up the bullet is out of the rifle’s barrel well before any of the rifle’s mechanical parts start moving. Everything considered, Stoner’s design should theoretically be just as accurate as a bolt-action of equal quality and this is proving to be the case.
Many of today’s semi-automatic tack drivers still have flip-up sights. They may be a leftover from their military heritage, but when they are installed, transitioning from optics to iron sights is a breeze. (top)
Easy-to-use, hand-turn windage and elevation adjustments located on the rear sight of this Fulton Armory FAR-15 Liberator Carbine make it easier for shooters to achieve match-grade accuracy with semi-automatic rifles. (lower)
When the Army MTU finished accurizing its M16 rifles, it helped develop and procure match-grade ammunition with 77- and 80-grain bullets and went off to the service rifle target competition wars. Within a remarkably short period of time, M16 and civilian equivalent AR-15-type match service rifles were dominating top level service rifle competition.
The incredible accuracy of these M16/AR-15 match service rifles is also demonstrated by their performance at 1,000 yards. At the National Matches, the Wimbledon Cup is shot with any rifle and any sights. Invariably this means a heavy-barreled bolt-action target rifle with a powerful scope firing a powerful, flat-shooting cartridge. There is a special trophy for the high-scoring shooter using a service rifle in this match called the Farr Trophy. In 2007, the Wimbledon was won with a score of 100-6X with a heavy barreled bolt-action, match rifle with a high-powered telescopic sight. Meanwhile, the Farr Trophy was won with an iron-sighted .223 semi-automatic service rifle shooting a 96-3X, only four points and three Xs lower.
While all this was going on, civilian AR-15 specialists were working their guns over into incredibly accurate heavy-barreled varmint-hunting rifles, action-competition rifles and even long-range target/sniping rifles. The introduction of flattop upper receivers with integral Weaver-type M1913 scope bases allowed the proper mounting of an enormous variety of scopes suitable for varmint hunting and target work.
These semi-automatic AR-15 varmint rifles are an absolute joy to hunt with, routinely achieving accuracy levels at 1⁄2 MOA or better. In a reversal of the norm, during our current war in Afghanistan the U. S. military Special Operations community copied the same basic civilian concept of a heavy-barreled, highly accurate AR-15 varminter and developed what it initially called the Special Purpose Rifle (SPR). It later received the official designation of MK12 Mod 1. These were M16A1 lower receivers fitted with flattop A3 uppers including heavy, free-floated match-grade barrels, match triggers, backup iron sights and optics. Firing 77-grain match-grade ammunition developed and produced by Black Hills, these SPRs routinely shoot well under 1 MOA and are deadly out to beyond 600 yards.
When observers from both the Army and Marines saw the SPRs in action and realized how effective they were, requests went out to get a similar weapon in the hands of conventional infantry troops. Currently both the Army and Marines are fielding scoped, flattop heavy-barreled M16 rifles for use by Squad Designated Marksman (Army) and Squad Advanced Marksman (USMC). These soldiers are giving a long-range engagement capability to infantry platoons and squads, which has proven to be a tremendous asset.
Many of today’s large-caliber ARs utilize ported muzzle brakes designed to redirect gas and reduce felt recoil. (top)
The flattop A3 upper’s popularity is owed to the wide variety of accessories, including lasers, lights and optics, that can be mounted upon it. (lower)
All of the semi-automatic accuracy work was not confined to the 5.56 mm cartridge. Reed Knight combined forces with Stoner to develop the SR-25. Basically it is a revival of Stoner’s original AR-10 in .308 Win., but redesigned to use as many M16/AR-15 parts as possible. From the beginning the SR-25 was conceived as a highly accurate .30-caliber sniper rifle. I have had the opportunity to shoot several SR-25 sniper rifles and they all proved to be extremely accurate, shooting five-shot groups well under 1 MOA with M118 military sniper ammunition.
One day, a couple friends and I had the opportunity to shoot a USMC M40A1 sniper rifle side by side with an SR-25 sniper rifle using the same match ammunition under the same field conditions. We fired five groups of five shots with each rifle. Both rifles averaged about 3⁄4 MOA with the M40A1 edging out the SR-25 by a miniscule margin. The single best group was from the SR-25. For all intents and purposes it was a dead heat. Since then, the SR-25 Sniper Rifle has been adopted by the Navy SEALs, the Army and the Marines, but so far only in small quantities. Thanks to the SR-25’s development, several other companies have stepped up to the plate to offer highly accurate .308 Win. AR-type rifles. The most prominent are the Armalite AR-10T and the DPMS Panther.
Occasionally I stumble upon some surprisingly accurate semi-automatic rifles. There was a scoped Springfield Armory SAR48 FAL-style rifle that shot 5-inch groups at 500 yards with one type of match ammunition. There was a scoped Ruger stainless Mini-30 that shot patterns instead of groups until I tried Winchester 7.62x39 mm hunting ammunition. Every group with the latter was sub-MOA. I also have a Colt AR-15 HBAR that groups well under MOA all day long when I’m using Black Hills 75- or 77-grain .223 Rem. match ammunition.
Eric Kincel, the head honcho of Vltor Weapons Systems, worked for Knight Industries. While there, he set out to build an SR-25 for himself using every technique available to get the ultimate accuracy. The resulting rifle will reliably shoot 1⁄4 MOA with select match ammunition and is the single most accurate .308 rifle I have ever encountered of any action type.
DPMS Panther Arms AP4LR-308
Heckler & Koch has also been a major player in the accurate semiautomatic rifle field. Its very expensive but astoundingly accurate PSG1A1 sniper rifle has a reputation of being able to shoot 1⁄2 MOA and the company’s more affordable MSG90 is not far behind in performance. The delayed-blowback roller-lock actions of these rifles, based on the German G3 military rifle, have some major advantages in achieving a high level of accuracy. The most significant of these is that they have no gas system hanging on their barrels.
The day of the accurate semi-automatic rifle has truly arrived.
Secrets to Semi-Automatic Accuracy
To get sub-MOA accuracy out of a semi-automatic rifle demands different approaches. First, semi-automatics are far more ammunition sensitive. This is because the proper gas pressure at the barrel’s gas port is necessary for reliable functioning and action timing. The latter is critical because it is important that there be no mechanical movement of the rifle’s parts until after the bullet is out of the barrel.
With semi-automatics, the cartridges are stripped from their magazine and chambered. It is imperative this be accomplished without any damage to the cartridge or the projectile. Thus, feed ramps and magazines are critical. A highly accurate semi-automatic rifle may commonly shoot notably better groups with one magazine compared to another for this reason.
On a semi-automatic, any part attached to the barrel must be attached in a solid manner to cut down extraneous vibrations. This is why Match M14/M1A rifle have their gas systems “unitized.”
If the rifle has a flash suppressor or muzzle brake, it is critical for alignment with the barrel to be as near perfect as possible. Also, it must have an adequate internal diameter so any bullet yaw upon leaving the barrel will not allow the bullet to kiss the inside.
With gas-operated semi-automatics, the gas port must be cleanly drilled without any burrs. For top accuracy the gas-port hole must be in the middle of the bottom of a rifling groove. Location in the middle of the top of a rifling land is nearly as good, however.
When headspacing a semi-automatic there are additional factors. The most important is when the bolt is fully locked; there should only be a minimum of forward movement left when there is no cartridge in the chamber. Otherwise, when the bolt chambers the round, inertia will push the bolt and cartridge forward to take up this movement, thereby effectively resizing the cartridge’s case and causing excessive headspace. Finally, one of the things that has allowed modern semi-automatic rifles to be so accurate is the development of much better trigger systems.
—CK
