Colt Canada, formerly known as Diemaco until their sale to Colt Defense in 2005, is the Canadian Forces’ primary supplier of small arms. They are most famous for the Canadian Forces C7 rifle and are lesser known for designing the first AR pattern flat top rail. Colt Defense and all their subsidiaries were purchased by CZ in 2021, now Colt CZ group.

The C20 is the Canadian Forces’ new 7,62 NATO designated marksman rifle. It is replacing the C7, a 20” barreled 5,56 NATO AR pattern select fire rifle with magnifying optic, for use in this specific role.

The C20 features an 18” barrel with a quick detach suppressor mounting muzzle break. This barrel is attached to a monolithic upper receiver. The receiver and hand-guard are combined into one piece piece and therefore the barrel is a truly free-floating. This system requires the use of a specialty barrel nut tightening tool that fits down the length of the handguard. Lewis Machine & Tool owns the patent (US8234808B2) to the monolithic upper. The buttstock was also designed and manufactured by LMT (Patent USD733247S1).

The charging handle latch is a slightly modified version of the classic Diemaco C7 ”ambidextrous” latch.

The lower receiver is borrowed from the Colt Defense CM-901 (Colt Modular rifle), this system was designed to be converted between proprietary 7,62 NATO and 5,56 NATO uppers. The C20 was not adopted by the Canadian Forces with any intention of being converted between larger and smaller calibers, the CM-901 lower receiver system was likely chosen because it happened what Colt already had developed their ambidextrous control system for.

CZ Colt Group’s generation 1 ambidextrous control system upgrades the magazine catch/release, bolt catch/release, and selector. The magazine can be released on either side. The bolt can be released and locked open on either side as well. The selector is a commonly recognizable ambi selector, it moves 90 degrees between the safe and semi-automatic positions.