The ArmaLite AR-10 Model AR103GN18 is a .308 Win/7.62 NATO semi-auto rifle engineered for shooters who demand speed and precision on the competition line. Built around a proven modular platform, this rifle combines match-grade componentry with practical features that make it a genuine contender in 3-gun and tactical rifle competitions. Whether you're stacking targets at distance or running dynamic stages, the AR103GN18 delivers the accuracy and reliability that separate winners from the rest of the field.

The 18-inch stainless steel barrel is crowned with ArmaLite's tunable muzzle brake, giving you the flexibility to dial in the recoil management that works for your shooting style and competition rules. A crisp Timney 4-pound single-stage trigger breaks clean and predictably—no creep, no surprises when you need a fast, accurate shot. The lightweight MBA-1 adjustable buttstock lets you dial in both cheekpiece height and length-of-pull so the rifle shoulders the same way every time, a detail that matters when you're running stages under the clock.

Ergonomics favor the competitor: an ambidextrous safety keeps you shooting without fumbling, the Raptor charging handle cycles smoothly whether you're right or left-handed, and the Ergo wide grip fits naturally in competitive holds. At 8.9 pounds, the AR103GN18 stays light enough to manage through transitions without fatiguing you over a long match day. Aluminum receivers keep weight down without compromise, and black anodized surfaces deliver the finish you expect. Out of the box, you'll find a 25-round Magpul PMAG included—the magazine choice of serious competitors.

This is a rifle that ships ready to compete. No hunting-focused compromise, no budget-cut shortcuts. Just the features and components that matter when milliseconds and inches count.

Key Features

• Timney 4-lb. single-stage trigger for fast, predictable breaks
• 18-inch stainless steel barrel with tunable muzzle brake for customizable recoil management
• MBA-1 adjustable buttstock with independent cheekpiece and length-of-pull adjustment
• Ambidextrous safety for right or left-handed operation
• Raptor charging handle with smooth, reliable cycle
• Ergo wide grip for competitive shooting positions
• Aluminum upper and lower receivers, black anodized
• Lightweight platform at 8.9 lbs. for reduced fatigue during competition
• Includes one 25-round Magpul PMAG

Specifications

Caliber	.308 Win / 7.62 NATO
Action	Semi-Auto
Barrel Length	18 inches
Barrel Material	Stainless Steel (1:10 twist)
Muzzle Device	ArmaLite Tunable Brake
Magazine Capacity	25 rounds
Receiver Upper	Aluminum, Black Anodized
Receiver Lower	Aluminum, Black Anodized
Stock	MBA-1 Adjustable (LOP & Comb)
Grip	Ergo, Black
Trigger	Timney Single-Stage, 4 lb. pull
Safety	Ambidextrous
Charging Handle	Raptor
Overall Length	40.3–41.5 inches (stock dependent)
Weight	8.9 lbs.
Included Magazines	One 25-round Magpul PMAG

Frequently Asked Questions

Is this AR-10 set up for 3-gun competition right out of the box?

Yes. The AR103GN18 ships with the features competition shooters rely on: a quality trigger, adjustable stock for cheek weld consistency, ambidextrous controls, and a 25-round magazine. You can run it straight to the line.

Can I adjust the stock for different body frames and gear?

Absolutely. The MBA-1 buttstock adjusts both length-of-pull and cheekpiece height, so you can dial in the fit whether you're shooting in shirtsleeves or wearing body armor.

What barrel twist rate does this rifle have?

The 18-inch stainless barrel has a 1:10 twist, standard for .308 Win / 7.62 NATO and suitable for a wide range of bullet weights.

What's included with the rifle?

You'll receive the rifle and one 25-round Magpul PMAG ready to load and shoot.