The initial production of the M3 was adequate to equip the cannon companies of the three hundred infantry regiments that had been forecast in the initial war plans. The M3 was the primary weapon of these companies, and appeared in the table of organization and equipment (T/O&E) from early 1944 (six, in three platoons of two) Often the cannon companies were integrated into the division artillery. The infantry used 1½ ton cargo trucks as the prime mover. In an assessment written after the war "The cannon company of 1943-45 failed to live up to the expectations of the force designers of 1942. The main problem was the substitution of towed low-velocity howitzers for the self-propelled versions as originally intended. This howitzer, the M3, had a shorter barrel than the regular 105-mm howitzer M2, possessed no ballistic shield, and had an effective range of only as compared to for the M2."
