LATE WWII THOMPSON
WAR
DEPARTMENT
TECHNICAL
BULLETINS
PART
II

Grip Mount Reinforcement Straps

We all have seen photos of the reinforcement straps typically mounted to the foregrip of Ml style Thompsons and have wondered why. We have also seen them on M1928s. Several rumored Thompson "EXPERTS" have suggested that this was a British modification or that all M1s should have them and if they don’t they are not an all correct WWII Thompson. Bull......oney!

Frank Iannamico wrote in his book "American Thunder", that the reinforcing bands were added to strengthen the foregrip mounting bars with

the riveted construction, due to these mounts being weaker in construction. The problem with the riveted grip mounts was that when a soldier exerted force to the forearm via the sling, which for some reason troops do when carrying a Thompson in combat, the forearm would bend and break. The reinforcement strap was a temporary fix to support the forearm.

There are several interesting remarks in this MWO. First, that the original requirement was issued on 4 Oct 43, but was canceled when the reinforcement straps were supplied too big and without all of the parts to assemble the strap. Secondly, that the original requirement was to include the M1928 was in error. Which maybe one of the reasons we see them on M1928s. Someone in the chain of command didn’t get the memo or just didn’t care.

Finally, in Frank Iannamico’s book he states that one contract was awarded to Winsted Hardware Co., Winsted, Conn., July 1944. However, this must have been the second contract to replace the big reinforcement straps. Also, listed are the complete listing of part numbers for the necessary parts for the assembly.