5

UNIQUE

AMMO

At a recent gun show, I got introduced to a box of ammo which has the above label. Made by

Frankfort Arsenal, Feb. 1945. As the label states it is for " Non-Standard Velocity for Helmet

Testing." Rounds were fired at samples of every production run of US M1 helmets. If the round

penetrated the production lot was rejected.

These cartridges were loaded for 880 ft/sec to be fired out of a 10.5" barrel. The only gun in the

inventory with a 10.5" barrel, I think, was the Thompson Submachine Gun. A standard 230 grain

Thompson fired cartridge has a muzzle velocity of around 920 ft/sec. So these rounds were to

simulate being fired by a Thompson at a certain distance from the helmet and if the rounds did not

penetrate a GI helmet then the production lot passed. Any volunteers to wear the helmet?