Service Rifle Buyer's Guide

The Service Rifle reflects the military roots of High Power rifle competition, and is intended to closely resemble the US service rifles (the current US service rifle is the M16/M4). Since the modern service rifles are not generally available to civilians, the rules allow the use of commercial equivalents (AR-15 for the M16). Certain specific modifications to the basic rifle are allowed as long as the external appearance, basic functioning, and safety features are not changed. Legal service rifles are the M1 Garand, M14/M1A, and M16/AR-15. This paper focuses on the AR-15 since it is the best choice when purchasing a rifle for competition.

Rules

High Power rifle is governed by rules set forth by the sanctioning bodies. The National Rifle Association (NRA) is the oldest and best known sanctioning body but the Civilian Marksmanship Program (CMP) is beginning to play a larger role in sanctioning local club-level matches. Each body has its own rules that share a common origin. Over time the rules have begun to diverge, with the CMP adopting a more liberal approach to the rules for the rifle. In general, a rifle that meets the NRA rules will meet the CMP rules.
This guide is not a substitute for the rules. Be sure to refer to the actual rules before purchasing a service rifle or any other gear.

What to Look For

20 inch barrel, heavy contour, with 1-8 or faster twist rifling - The rules limit barrel length to 20 inches; an AR with a 20 inch barrel is "standard". A heavy contour barrel whips and flexes less during firing and handles the heat of rapid fire better without changing point of aim. Flash hiders are permitted but are not required and do not help or hinder accuracy. A twist rate of 1-8 (the bullet spins once every eight inches it travels) or quicker is necessary to accurately shoot bullets in the 75 grain class or heavier, which is important when shooting at 600 yards.
Float tube or equivalent quadrail handguard - The use of a sling is critical to accurate shooting; without a sling you are just wasting ammunition. The sling must be tight to be effective, and that places a lot of tension on the front sling swivel. Standard AR-15s mount the front sling swivel on the barrel; a tight sling will bend even a heavy barrel enough to change the point of impact. A good competition rifle incorporates a float tube inside a standard handguard or a floating quadrail handguard that is attached only at the receiver. The front sling swivel is mounted to the float tube, and since the float tube does not contact the barrel the tension of the sling extends back to the receiver and does not change the point of aim.
Military-style sights on an A2 carry handle
Iron sights must be the type normally issued with iron-sighted M16-A2s, with the front sight on the front sight tower and the rear in the normal position in the carry handle. Flip-up and other aftermarket sights are not allowed. Rear sight hoods and replaceable (smaller) apertures are allowed and prefered. Look for 1/2 or 1/4 MOA per click sights. The front sight must be a post.
Scope on an A4 receiver
Almost all competitors now use telescopic (optical) sights. Scopes have been allowed for the past several years, consistent with the military's switch to optics for combat. Scopes may be fixed or variable power but are limited to 4.5 power with a maximum objective lens diameter of 34mm. The scope should have 1/2 or 1/4 minute adjustments (not "mils" or other units) and "target" turrets that are marked in minutes of angle and adjustable using fingers alone (no coins or other tools). Click-adjustable turrets are a must since they can be adjusted by feel without looking at the turret. The reticle must be fine enough to permit aiming accurately within about an inch at 200 yards under all daytime lighting conditions. Very fine crosshairs or very small target dots are often hard to see against the black aiming black and are generally not favored for that reason; all we are trying to do is center the reticle on a 6 MOA black circle (you won't necessarily be able to see the scoring rings). Lighted reticles generally offer no advantage. Many competitors use a lens reducer - a clear disc with a small hole in its center that fits over the rear lens of the scope. This device forces the shooter to look through the optical center of the scope, reducing the effects of parallax. Acceptable scopes may range from $300 to several thousand dollars, and in general you get what you pay for in terms of clarity, function, repeatability, and reliability. Most major manufacturers make suitable scopes, and Vortex, Leupold, and Nightforce are often seen on the firing line.
Don't be tempted to mount a scope on an A2 carry handle - not only will it be too high to meet the rules, it will be impossible to use well. Get an A4 (flat top) upper receiver and good cantilever scope mount designed for prone shooting (normal scope rings will not mount the scope forward far enough).
.223 Rem/5.56 NATO - The rules require that the rifle be chambered in 5.56 NATO/.223 Remington caliber. Most good competition barrels will have a Wilde chamber or some variation of it, which is much better than a standard military or commercial chamber.
Buttstock - The rules permit a fixed or adjustable buttstock. The buttstock cannot have an asymetric or adjustable cheek rest or buttplate. A standard A2 buttstock is inexpensive and works for most people. A1 buttstocks, which are a bit shorter, are available and legal. If you want an adjustable buttstock, look at the Magpul UBR. Most adjustable buttstocks are wider than a standard A2 butstock, making it difficult for some shooters to center their eye behind the sights.
Pistol grip - Only standard A1 or A2-style pistol grips are allowed by the NRA. Other designs offer little or no advantage.
Trigger The rules require a curved trigger with a minimum pull weight of 4.5 pounds, and a good trigger is critical to getting the most accuracy out of any rifle. A standard AR trigger is "single stage", which has a consistent pull weight and travel from the time you start pulling to the time the rifle fires. A "two-stage" trigger has two distinct stages. Most of the weight is in the first stage; you "take up the slack" and pause. The final stage takes just a little more effort. The benefit of the two-stage trigger is that it is a 4.5 pound trigger but feels like a lighter-weight trigger. Really good triggers are fully-adjustable for first and second stage weight, sear engagement, and overtravel. Two-stage triggers that come with competition-ready rifles are generally pretty good, and are easily upgraded later. Giesselle (the Hi-speed National Match model) is a very good and popular manufacturer of very high quality triggers. Get a two-stage trigger.
Sling - While not required by the rules, you must use a sling to make the most of your ability and the rifle's accuracy, and you will get no respect or help from the other shooters if you do not use a sling. The rules limit the sling, if used, to be either a standard military "M1" web sling (WWII/Korea) or a M1907-style (typically leather) sling. The sling takes a lot of abuse and is critical - use a good one and replace it when it wears out.
Extra weight - Many shooters add weight to their rifle to balance the weight and slow down the normal movements while aiming. Lead weights that fit inside a standard A2 handguard and in the storage compartment of a standard A2 buttstock are available and can add several pounds to the rifle. Weights are available for some adjustable buttstocks and quadrails, but not all types support the addition of weight. Rifles weighing up to 18 pounds are not uncommon.

Don't Get

Certain popular AR-15 features are either illegal according to the rules, hurt the accuracy of the rifle, or are just a complete waste of money.
Front Pistol Grips - don't bother with front pistol grips or other appendages. They are either not permitted, unusable, or detract from the accuracy of the rifle. Handstops and palm rests of any kind are not allowed.
Flashlights/Lasers - flashlights and lasers are useless in precision shooting.
Muzzle Brakes, Compensators, Suppressors - besides being illegal in competition, muzzle brakes and compensators distract the other shooters and will make new enemies on the firing line. Suppressors are neither permitted nor conducive to accuracy.

Recommendations

If you have an M1 Garand or M1A already, use it and spend your initial money on a good coat, spotting scope, and scope stand. If you already have an AR-15 that doesn't quite meet the rules, it can probably be fired as a match rifle. Most High Power matches also allow match rifles. If you need to buy a rifle, get an AR-15 that meets the rules for service rifles.
If you have good eyesight (can see the front sight clearly without a lot of correction), you might consider starting out with iron sights. Not only are the rifles less expensive (no scope or mount to buy), iron sights teach good marksmanship fundamentals. Iron sights are suprisingly effective. Rifles with iron sights are increasingly rare, though.
The easiest way to get started is to buy a complete National Match ("NM") AR-15 A2 (iron sights) or A4 (flat top) rifle from Rock River or other vendor. If you opt for the A4, a cantilever one-piece scope mount and a Crossfire II 1-4x24 scope from Vortex Optics is a good basic scope/mount option. There are many other options, but this one will take the new shooter a long way.
You will not find a good match-quality AR-15 service rifle in a retail store.
The Lower Receiver Consider starting with a standard A2 fixed buttstock. Not only is it less expensive than a good adjustable buttstock, it eliminates one variable that might get in the way of learning to shoot the rifle. Look for a lower with a 2-stage, 4.5 pound trigger. Rock River makes a reasonably good lower with a decent trigger. The lower receiver is the controlled part of the AR-15, so you'll need to go through a licensed firearms dealer to get it.
The Upper Receiver Look for an upper that is advertised as "National Match"/"NM" or "DCM-legal"; Look at White Oak or other on-line suppliers specializing in match-quality rifles. Upper receivers are not controlled, and can be purchased on line without going through a dealer.

Resources

2026 Civilian Marksmanship Program rules: (https://thecmp.org/wp-content/uploads/2025/12/2026-Highpower-Rifle.pdf)
2025 National Rifle Association rules: (https://competitions.nra.org/media/10180/2025_high_power_rifle_rules-2.pdf)
White Oak (https://www.whiteoakarmament.com) (uppers, scopes, parts, tools, accessories)
Rock River (https://www.rockriverarms.com) (lowers)
Brownells (https://www.brownells.com/) (parts, tools)
Geissele (https://geissele.com/) (triggers, scope mounts, quad rails)
Creedmore Sports (https://www.creedmoorsports.com/) (accessories, parts, most gear needed for high power match shooting)
Leopold (https://www.leupold.com/) (optics)
Night Force (https://www.nightforceoptics.com/) (optics - Competition SR Fixed 4.5x24)
Vortex Optics (https://vortexoptics.com/) (optics - Crossfire II 1-4x24)
Turner Saddlery (https://turnersling.com/) (1907-style slings)
Ron Brown slings (https://servicerifleslings.com/) (1907-style slings)