Transitional UMC .22s with Case Mouth Letters


Here is a selection of UMC .22s with case mouth letters. I guess these are notifications of transitions between different types of powder mainly.

CLiCK this picture for a LARGER one

Here is a little closer up pictures in the same order:

Ones I have:
.22 Short I (2 variations pictured, brass and copper case)
.22 Short A
.22 Short S-
.22 Short U
.22 Short f (edit: this one is actually an S)
.22 Short L
.22 Long L
.22 Long S
.22 Long S-
.22 Long U
.22 LR S-
.22 LR C
.22 LR G
.22 LR L
.22 WRF S

Anyone have any more info on what exactly the letters mean? (I will edit these as info becomes available)
S = Smokeless
S- = ??
I = ??
A = ??
C = ??
G = Greased
U = Ungreased

  • = ??
  • = ??
    O = ??

Anyone else collect these?
Anyone else have any other letters?



Here is Appendix F from Barber’s book The Rimfire Cartridge 1957-1984.
If you don’t already have it, and your interested in Rimfire cartridges, I would consider it a “Must Have” text.

U = Ungreased
G = Greased

Never heard of the " f " you list. Are you sure it is not some other letter?



upon closer inspection I believe it may be an S

I do have Barber’s book. I did not even know about this appendix. Thanks!

Also, a couple of these are definitely not listed in that appendix too (He doesn’t list the “S” as being used for any UMC one, when i have it on a short, long, and a WRF, and the C for the .22 LR,) so I am still wondering if anyone else has a more up-to-date list?


Aaron–Yes, I agree that your " f " is actually a poorly stamped “S”. I suggest you might want to modify your original post to delete the " f " and say it is a “S”, so that anyone saving your information won’t be looking for an " f " in the future.

The lack of an “S” listing for Remington-UMC surely must be an oversight by Barber as it is one of the most common case mouth letters found.

I am not sure that UMC ever used these case mouth letters. At least in my experience, I have only found them in Remington-UMC boxes.


Will Adye-White did a long list of these that was published in a past IAA Journal.
You will then see a list of other fools that collect these markings. (speaking for myself)


Post Edited. Thanks all who emailed me what I needed =)


I am not sure that UMC ever used these case mouth letters. At least in my experience, I have only found them in Remington-UMC boxes.[/quote]

Also, if you look in Journal 466, page 44 at Lou Behling’s response to something in Will’s article he shows a record (presumably from his research in the Remington records room, while on the Remington Society of America’s research team) dated Dec. 1903 where UMC was ending its experimental use of a new powder, and using the S casemouth marking on .22 Short cases that were sent to foreign countries.

This date would obviously be UMC and not Rem-UMC.



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