The M1 was essentially the British 6 Pounder anti tank gun introduced into US service in spring 1943 following the American experience in the North African campaign.

It was considered too heavy and was not adopted by the airbone or cavalry but by 1944 the M1 was the standard anti tank gun for US infantry on the Western front although availablilty of different ammunition types, such as HE, limited its use. US units were sometimes able to get HE ammunition from the British Army.

As with most early war towed artillery, it was less effective against bigger German tanks and mobility was compromised in offensive situations although it remained reasonably effective in defence. An infantry division complement was 50 guns.

The M1 was also provided to the Free French, Russian and Brazilian armies under Lend-Lease arrangements. Captured guns were redesignated 5.7cm Pak 209(e) and 5.7cm Pak 202(a) by the Germans. They remained in active service with armies around the world as late as the 1970s and are believed to still be used in some South American countries and in static defence of outlying Chinese island garrisons.