Meet the T91.

The National Interest
Date: November 24, 2019
By: Charlie Gao

Key point: The T91 will remain an interesting footnote in the history of the M16 platform as one of the first truly viable external short-stroke piston ARs to reach widespread production.

Despite early problems in Vietnam, the American M16 made a major impression on many Western-aligned nations in Asia. The Republic of Korea, the Philippines, and Singapore began license producing the M16A1, and many other nations bought M16s straight from the United States. However, Taiwan bucked this trend, developing the T65 rifle in the 1960s. However, the T65 is hardly a clean-slate design, practically copying the M16 design in the lower receiver and heavily emulating other elements in the upper receiver.

The primary difference between the T65 and the M16 is the incorporation of a short-stroke external piston gas system instead of the internal piston gas system used in the M16.  But unlike Armalite’s AR-18 the rest of the design is practically unchanged from the M16, retaining the recoil spring in the buffer tube and the cylindrical bolt carrier group of the M16, as opposed to the dual recoil springs in the receiver and “boxy” bolt carrier group of the AR-18.

There are also differences in the sighting and handguard setup of the T65, with a different triangular handguard being used on the T65 and a simple non-carryhandle rear sight used instead of the M16’s carry handle rear sight on the original T65. In theory, this could make integration of optics easier, but the receiver was not tapped for the addition of an optic and a M16 carry-handle style rear sight was added on the T65K2 variant.    [FULL  STORY]