3

This led me to more closely examine the box magazine supplied

with the Model 1927A1. The Type XX box magazine was made

by W.P.S. (Worchester Press Steel Co.) during World War II. The

cartridge support on the top of the follower had the back end of it

ground down and welded to form a ramp. The ramp was created

so that since there was no empty magazine trip in the gun, the

bolt, which fires from a closed position, would not slam into the

back of an empty magazine. Instead it would hit the ramp and

push the follower down and close on an empty chamber.

Remember, without a means for the follower to operate a maga-

zine trip, in the trigger frame, the bolt would come forward and

hit the back of the magazine. The ramp allowed the bolt to push

the follower down and close on an empty chamber.

(Above) The magazine supplied with the

Model 153, is a WPS WWII magazine, with

the cartridge support on the follower modi-

fied for the semiautomatic Thompson.

(Above) Front view of the magazine well on

the trigger frame showing the in the white

metal spacer inserted.