User:Casperthelazyghost/ArmaLite AR-18

Influence on later rifle designs
When the AR-18 was designed,  a plethora of different methods of gas and recoil operation existed in self-loading intermediate caliber rifles. Since then self-loading intermediate caliber rifles have converged toward three methods of gas operation. These are: AR-15 style Direct Impingement, the AK-style long stroke gas piston and the short-stroke gas system found in the AR-18 rifle. While the AK-style and AR-15 style systems of gas operation are the first and second most produced intermediate caliber rifles of all time,the AR-18 gas system is the ancestor for the majority of short stroke gas systems found in selective fire military rifles. The AR-18 mechanism is the basis for many rifles in major military service. Rifles which use a copy or derivative of the AR-18 gas system include: German HK G36, HK416, HK433, FN-SCAR, Steyr AUG, CZ 805 BREN, Chinese QBZ-95, Daewoo K1, HOWA Type 89, SAR-88, T-91 and British SA80 family of weapon systems.

In some cases, designs borrow more than just the AR-18's gas system. Successive rifle designs borrow other components such as the bolt carrier group or upper receiver. The HOWA Type 89 is an AR-18, modernized to fit the needs of the Japan Self-Defense Forces. The Singapore SAR-88 and Taiwanese T-91 utilize a complete AR-18 upper receiver. Early British SA80 prototypes featured ArmaLite produced AR-18 upper receivers mated to a prototype stamped metal bullpup lower receiver. The finalized SA80 weapon systems use the AR-18 gas system and bolt carrier group. The Remington Adaptive Combat Rifle derives its bolt carrier group from the AR-18.