45 Remington-Thompson for the M1923 TSMG

Not really a serious collector, just have a few odd balls. I am a retired Ordnance officer and still enjoy the subject. My question is about a round that I have headstamped REM-UMC 45ACP, but it not like any others I have seen. The case is 1.080" long and the bullet has a more pointed profile. Any ideas as to what this may be.

Sounds lik e a 45 Remington-Thompson for the M1923 TSMG. Fired a 250gr bt at 1200 fps. Five M1921 TSMGs were modified to shoot this ctg.


Here’s a recent thread.

iaaforum.org/forum2/viewtopic.ph … t=thompson


Here’s a picture of the 1923 Thompson, as it was envisaged being used;

There are two different bullets (different ogives) loaded in this round by Remington, both pointed, but one more rounded than the other.