[2] The M3 consisted of a 76.2 mm (3 in) barrel 50 calibers in length, which had a removable liner and a semi-automatic vertical sliding-wedge breech.

The barrel had a hydro-pneumatic recoil system and when fired the breech ejected the shell casing and remained open until a new round was loaded.

The M2A2 cruciform carriage had a circular center section and four perforated steel outriggers for stability.

The carriage had pneumatic tires, electric brakes and was capable of being towed at high speeds.

The gun was provided with a set of equilibrators and was capable of both high angle fire +80° and 360° of traverse.