Changes
| '''Long barrel''' || 10.5 inches || None || || '''400''' || Installs a long 10.5 inch barrel with corresponding front sight.
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| '''Super Buntline''' || 12.5 inches || Weight +1 tier || || '''500''' || Installs a super-long 12 .5 inch barrel with corresponding front sight, inspired by the Buntline Special.
|}
| '''Long barrel''' || 9.5 inches || None || || '''400''' || Installs a long 9.5 inch barrel with corresponding front sight.
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| '''Super Buntline''' || 12.5 inches || Weight +1 tier || || '''500''' || Installs a super-long 12 .5 inch barrel with corresponding front sight, inspired by the Buntline Special.
|}
| '''Carbine''' || 14.5 inches || Muzzle: Standard devices<br/>Bayonet compatibility: [[M9 bayonet]] || [[Colt M4A1]] || '''300''' || Installs an M4 style 14.5 inch barrel, which provides a compromise between performance and weight. Considered to be the standard length for AR-15 rifles.
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| '''Competition''' || 12 .5 inches || Weapon becomes Class 2<br/>Muzzle: Standard devices || || '''600''' || Installs a short 12.5 inch barrel designed for competition shooting such as 3-gun.
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| '''Subcarbine''' || 10.5 inches || Weapon becomes Class 2<br/>Weight -1 tier<br/>Muzzle: Standard devices || [[Colt Mark 18 Mod 0]] || '''800''' || Installs a very short 10.5 inch barrel designed to minimize size and weight as much as possible, at the cost of ballistic performance.
