COLT CR6933 SBR 5.56 11.5″ 30RD BLK

Description

The Colt CR6933 is a purpose-built compact carbine designed for work in confined spaces where a standard-length rifle becomes a liability. It suits professionals, serious hobbyists, and anyone who wants a short-barreled M4-pattern platform built on genuine Colt military-production components rather than assembled from aftermarket parts.

The 11.5-inch barrel runs a carbine-length gas system, which on a barrel this short keeps the gas port closer to the chamber than a mid-length arrangement would. That geometry raises port pressure relative to what you’d see on a longer barrel, producing a sharper, faster bolt cycle. The trade-off is a snappier impulse, but on a carbine intended for close-quarters use, the cycling reliability that comes with that tuning is the priority. The barrel is chrome-lined and phosphate-coated — chrome lining reduces friction and resists the heat and corrosive fouling that short barrels accumulate quickly, while phosphate handles the exterior. The 1:7 twist rate stabilizes heavier projectiles, including 75- and 77-grain loads, which is where 5.56 performance tends to peak from a short barrel when velocity is already reduced.

The upper and lower receivers come off the same Colt production line that supplies military contracts. The front sight base is the F-height profile correct for a flat-top upper, and the gas block is the A2-style unit with the integrated post sight. Factory accessories include a Magpul MBUS Gen II rear sight and a 30-round Magpul magazine. The M4 stock rides on a 4-position receiver extension, keeping the collapsed length short enough to make the platform genuinely compact while still offering a usable length of pull when extended. Mounting a suppressor over the muzzle is where this carbine’s overall length still stays manageable, which is why the 6933 profile has remained a reference configuration for compact 5.56 builds.