Cal .45 M15 shot cartridge (Initially thought to be experimental)

I picked up what I thought was a .45 ACP blank when I was in Salt Lake City last month. However, I decided to look in HSW Vol II, as I thought the shape was unusual and it has a red card wad.

It turns out to be an experimental shot cartridge. HSW lists two varieties. One with a rose petal crimp (A) and the other (B), which is the one I have.

I believe that the use of the term “Experimental” with the cartridge shown is a misnomer. With that headstamp, that shot cartridge picture is designated “Cartridge, Shot Cal…45 M15.” There is no “X” preceding the its designation. This was normal, issue ammunition for use in hunting small game in emergency survival situations.

Wads on these rounds range in color. I have not seen one with a wad I would describe as “red,” but I am NOT disclaiming the possibility they exist, as colors I have seen are buff, dark orange and purple. These wad colors are also prone to fading over the years.

The pre-production version of this cartridge (I think a more appropriate term rather than “experimental” in the case of these rounds but, of course, that is open to interpretation) is identical other than overall cartridge length, and has a pale yellow over-shot wad. It is slightly longer in the “neck” than that of the production rounds, and the headstamp used was the normal commercial “REM-UMC 45 ACP”.

Cartridge lengths (nominal):

Preproduction REM-UMC 45 ACP - 1.2730 inch (32.34 mm)
Standard issue loads R A 4 and R A 45 - 1.2525 inch (31.81 mm)

Below are pictures of some box variants, as well as an instruction sheet contained in some (perhaps all) of these boxes.

Top box: Original box R A 4 with waterproof wrapping.
Second from top: LOT RA 5014
Third from top: LOT RA 5033
Bottom box: LOT RA 5043 (R A 45 headstamp)


John Moss

1 Like

Thanks John,

I may have misread the information I found and obviously need to go back and revisit it. However, I am about to rush out the door.

HWS Vol II page 26. Fig. 18. shows a drawing of two types of cartridge (designated experimental) and gives the HS as being either RA 42 (type A) or RA 4 (type B). I need to check the OAL as I note there are differences between those shown in Fig. 18. with another cartridge that is also shown.

In the text Frank notes the case had a brass extension tube loaded in the case. and in the addendum he notes the illustration A & B are reversed- A should be B & B should be A

Mayhem - Thanks for the HWS reference. I had not read it in a long time. I do not believe your cartridge is the one described as the T29 “all brass” round made experimentally by using a brass extension tube loaded in the case (headstamped RA 42), which is the cartridge referred to in Fig 18., although I believe, from what is in the text, that the caption of Figure 18., which shows the headstamp of Cartridge “A” as “R A 42” and that of Cartridge “B” as “R A 4,” is erroneous, reversing the headstamps of the pictured cartridges from those as described in the text above the picture. This is, by the way, if I am interpreting it correctly, the first time I have found an error like that in Frank, Bill and Gene’s book. I believe that your very good picture shows a case that is one piece, not an inserted tube, from top to bottom. I also think in figure 18 that the overall case length measurement of cartridges “A” and “B” are reversed, as the drawings are to the same scale, and the Cartridge “B” is clearly longer than Cartridge “A”, even though the supplied measurements would indicate the opposite. (in truth, it is likely that it is the cartridge drawings that are reversed).

When it gets into the second paragraph of the same page, but the column to the right, about "The T29 cartridge as finally developed...." there is another entry that confuses me, as it describes an overall length of the cartridge on production drawing of the M15, from March 6, 1944, with an overall length of 1.265 - .030.  I don't know what that  second figure (.030) means, and it is not explained.  If what appears as a dash is actually a minus sign, that would bring the OACL length down to very close to the one I measured, but if it is a dash, I haven't a clue to what it refers to.  

I think that first, we need an OACL for your cartridge, and second, we need a picture of the over-shot wad to determine the exact color. “Red” can cover a lot of shades, and it is not one of the colors mentioned for experimental rounds in HWS II. If purple, bright or faded (where it could take on a reddish look), that would insure your cartridge is a production round).

I do appreciate your supplying of the HWS page and illustration number. It made this easier to evaluate.

P.S. While I was typing this Pete de Coux supplied a comment, which I can’t read as I type this. I will go ahead and post this, but it may duplicate things Pete said.

O.K. Pete noted the difference in the addendum, which I did not have at hand. I suspect I must have it in my library, but didn’t grab it when I brought the book itself up to my office. I see it validates what I said about “reversal.” Thanks’ Pete.

Edited to include the last paragraph.

John Moss

Thank you both for your comments and clarification. I agree with your assessment of my round and will get the information as soon as I get back home.

Is there anyway to distinguish a T29 developmental from the adopted M15 or is that the one John described with the commercial head stamp?

HWS ll does not seem to indicate headstamps found on the T29.


Bills Book doesn’t show the REM-UMC 45 ACP as a prototype, but it has the pale yellow/greenish over shot wad, the color of which was changed very early on, and I can’t personally see any reason why they would use that headstamp on a military issue round after the adoption of the T29 as the Cartridge, Shot, M15. Further, my specimen is longer, as noted in my original comments, than any of the military headstamped rounds I have. Of course, Bill had two or three variations, likely, for every one I have. All I know is I got the commercially-headstamp round from a knowledgeable source, and was told it was a pre-production round, which with the commercial headstamp, yellow wad, and non-standard length (for an M15) case, makes sense.


Hi John,
I have a M15 identical to Mayhem’s and yes it does have a (faded) red wad, I can post a photo of it if later on when we have light if needed.


OK - I have learned another important lesson and that is not to rely on my memory! I’ve just found the cartridge (yes - I had actually misplaced it) and the top wad is brown. It is a dark tan brown but may be discoloured. It doesn’t however resemble red at all. I must have been thinking of Tony’s!

The OAL is 1.253" which would confirm that this is indeed the M15 (T29) cartridge, as John initially pointed out. I’m unsure if I really didn’t pay proper attention, or was excited to think I had an experimental round and looked at only what might confirm this. Either way I am glad to have it correctly identified.

Mayhem - I do the same thing myself. I rely on my memory sometimes because I don’t have time, or don’t feel like trudging down the stairs to my library. I used to have a very good memory for small details, but guess at 80 years old, it is fading. Your pictures were very good and pointed out some features indicating a standard issue round. I, for one, appreciate very much you opening the thread, as it turned into an interesting discussion, and one from which I learned some things about these cartridges. Thank you.

Tony, it would still be great if you could post pictures of that red top wad. I have never seen one and Bill W. didn’t mention that color of top wad among all the different ones he had. The photo would be a fine addition to this thread. Thanks.

John Moss


Thank you very much for that additional information.


To all that contributed to that post !!
I have 2 loadings like as shown above HS RA4 one has a red top wad seal the
other one has an egg shell type colored seal,I do not know if this is any help in
this case.

Three from my 45 Auto collection: One on the left head stamp R A 4 light brown/tan
One in middle head stamp R A 45 black? paint on primer dark brown/tan
One on the right head stamp R A 4 dark red? almost purple

99% are R A 4 & I think perhaps two are R A 45 examples. Some are close enough to be duplicates but only the bottom row is logged into my book so I haven’t had a chance to sort the dups. out
Edited to add The lime green upper right has a REM-UMC 45 ACP headstamp

Isn’t the lime green one on the far right of the top row a REM-UMC ?

Right on the money Bill, Good catch
I just pulled up shot loads & didn’t look at the headstamp

Pete - thanks for that picture. There are certainly two there I would call red, and I do not think for a minute they are faded purple ones, plus a dark yellow one, not at all like the one I described as Yellow/green, with the commercial headstamp. Far better collection than mine. I have never even seen the red or bright yellow over shot wads in these rounds.

Thanks for posting.


Here are a couple “different” .45 ACP Shot-shells. Sorry I couldn’t get a clearer photo… the headstamp is L C 7 6. Any guesses?

PS: I’ve had these a long time… since 1976 or 77. I had about 100 of them at one time.

These are either commercial shot loads on altered rifle-cartridge cases - either .30-06 or 7.62 x 51 NATO/.308 Winchester - made by small companies, or actually home-made by a reloader. I have samples of both in my collection, although none with quite that shape at the neck and mouth. The one pictured seems to have been made from a disassembled live round, as the primer crimps do not look disturbed in you picture. I doubt very much if they are military loads. I am not aware of any military shot loads from the era of the date on those headstamps, not any ever made at Lake City Arsenal.

John Moss