REM-UMC 45ACP Riot Load

I was going through some 45ACP cartridges today and came across a couple headstamped REM-UMC 45ACP that look like normal ball rounds but when you shake them it sounds and feels like there is a ball inside. What do I have? Thanks; Jack

Those rounds are a Remington multi-ball loading intended for the Thompson Submachine gun. Remington’s box-label name for the load was ".45 Automatic Riot Smokeless. The bullet is in five parts - Jacket, round ball under the nose and on top of three flat, lead wafers. Total bullet weight is 205 grains. I have encountered this load with three headstamp variations:

REM-UMC 18 No case cannelure, domed, plain copper primer.

REM-UMC 45 ACP No case cannelure, domed, nickel primer with “U”.

REM-UMC 45 ACP No case cannelure, domed, nickel primer.

The box label sample I have, which is an original H.P. White Labroatory label card, their collection number 5506, revelas that the original box was labeled for standard 200 grain FMJ RN ammunition and was then completely over-labeled. Advice on one side label says "Specially adapted for .45 Automatic Colt and Thompson Sub-Machine Gun.

The other side label indicates: These cartridges are made with a specially constructed bullet composed of five pieces. These separate after leaving the muzzle and cover at twenty yards a circle approximately two feet in diameter.

I suspect in the case of the round headstamped “REM-UMC 18” that it is an instance of surplus cases being used. These rounds probably date from around or after 1921, the year the TSMG really became available, and I do not believe they were ever officially adopted by the military.

If desired, I can post a picture of a factory cutaway cartridge taken from an old, tattered and totally incomplete leatherette salesman’s sample case. and a picture of the box label as it is arranged on the H.P. White Laboratory card.

I hope this is of some help to you.

Thanks John and please post the photo; Jack

Factory cutaway Remington .45 ACP Riot Load, showing bullet arrangement. What cannot be seen is that the top wafer is about the same thickness as the other two, but the top portion of it curves up to a reduced diameter from the bottom portion. That is hidden in shadow. It appears almost like a squashed, lead SWC …45 bullet.

Below the cartridge are pictured the three headstamps (actually two headstamps and one with a marked primer and another with a plain primer but of the same headstamp) I have encountered.

The H., P. White Laboratory collection catalog card for the Remington-UMC .45 Riot Load box label. Self-Explanatory.

Collection of John Moss


Nice find!


Very interesting information. I had previously a different understanding of what this load consisted of. Clear as can be, now!

Before I go though my piles of old .45 ACP…

Other than the possibly loose insides rattling, is there any other distiguishing appearances to look for? Not having a case cannelure perhaps or maybe the bullet jacket profile? I assume total cartridge weight would be less than a modern ball with a 230 gr. projectile but 200 gr. was also used and that would be close to call.


Well, the bullet has a tiny difference in ogive compared to 230 grain ball, but I can’t describe it hear. The case has no cannelure, but then, some other Remington rounds don’t either. Headstamp and primers are normal. Weight, as you pointed out, will be similar to a round with a 200 grain bullet, but most of those rounds have a case cannelure.

Don’t really see any need for any other identification - every one of these I have had rattles like hell when you shake it, and you can feel movement when you just pick it up. I will probably have one of these at St. Louis - the one with commercial headstamp and no primer marking.


Thanks for the additional information. The rattle test is easier than comparing ogives!

Once again, you’re the source…


I just rattled out a third one. Are these quite common?

They are not all that common, but certainly aren’t rare. I would call them uncommon, overall. However, my experience is like yours. When you find one in a group of rounds, you often find more. I found 6 of them once in a dime box. Still, over the years, I can’t say that I have seen a huge quantity of them.