T86 assault rifle The T86 ( 聯勤 Type 86 ) assault rifle is a gas - operated , magazine - fed , air - cooled assault rifle . It is the second original rifle design conducted by the 205th Armory of Combined Service Forces , Republic of China ( Taiwan ) . Though it saw limited production and service after a protracted development process , it became the basis of the T91 Assault Rifle currently in volume production for the ROC armed forces . History . Development of the T86 started in 1992 , with the stated objective of replacing the venerable T65 series . Several radical concepts , such as caseless ammunition , were explored but ultimately rejected due to high risk . Still , the XT86 prototype revealed to the public in 1996 demonstrated several innovative features and significant departure from US influence in firearms design . However , the ROC military was more confident in the tried - and - true T65 design , and instructed the 205th Armory to redesign the rifle . The XT86 pre - production model rolled out in 1997 showed a return to the T65 ' s features , especially the T65K3 carbine . The T86 design was finalized in 1998 and officially named the 5 . 56 mm T86 Combat Rifle ( 5 . 56公厘T86戰鬥步槍 ) . Design . The finalized T86 design is an evolution of the T65 series . It inherits the short - stroke gas piston operated system from the T65 as well as the rotating bolt design . Upper and lower receiver are made with aircraft - grade aluminum . The side - folding metal stock on the prototype was replaced with an M4 carbine style polymer telescopic stock and buffer mechanism . The polymer handguard from the prototype was retained . The controls of the T86 are similar to the T65 and M16 . The T86 has a 4 - position selector with safe , semiautomatic , three - round burst , and automatic settings . Like the T65K2 , T86 utilizes an M16A2 - style front post / rear peephole sight . The rear sight is adjustable for windage and elevation . One notable difference is that the T86 does not have a forward assist , and the brass deflector is shaped differently . The T86 has a barrel with flash suppressor . The rate of rifling twist is one twist in . The bore is chrome - lined and the T86 can fire all 5 . 56x45mm NATO standard ammunition . Magazines used by the ROC military feature two protrusions on each side to avoid over - insertion , but standard STANAG magazine s are compatible . The T86 is modular and can be field - stripped without using special tools . The gas piston system and the trigger assembly can be removed as complete assemblies for maintenance , reducing the risk of losing small parts . Accessories . An attachment point is provided on the carrying handle for an optional scope mount . The T85 40 mm grenade launcher , standard issue of the ROC Army , may be mounted on the T86 carbine . Production and Usage . Contrary to initial expectation , ROC Army and Marine Corps did not order T86 carbines in large quantities . Defense budget priorities during the late 1990s forced ROC military to delay the replacement of T65K1 and T65K2 assault rifles . A small quantity of T86 did enter service with the ROC Navy Underwater Demolition Team and underwent rigorous trials in widely varied environmental conditions . Jodanian royal guards and special troops are reported armed with Taiwan made T86 carbines in the parade .