"REM-UMC 38 AMU" match cartridge

This Army Marksmanship Unit ammo is supposed to be rimless but it looks rimmed or SR to me,

I shot lots of .38 Special when on the Army’s Pistol Team in the late '70s, early-'80s. We had several revolvers and semi-autos for them. I not, however, familiar with a “38 AMU”.

1 Like

John - There was a Forum thread c. December 2016 on this cartridge entitled “Colt Model 1911 pistols and the .38 cartridge.” I don’t know how to provide a direct link to it.

That was 3 years ago, so it probably won’t hurt to go over it again.

The .38 AMU cartridge was designed by the Army Marksmanship Unit at Fort Benning, Georgia, the date of the development generally being given as 1960. Wikipedia, last time I looked, gave a date of 1964 for it, but that is incorrect, as an article appeared in the August 1963 issue of “The American Rifleman,” Pages 42-43, and the opening line of the article refers to the beginning of the development as "Several years ago,…, making the 1960 date completely feasible.

The first cartridges were likely made by Remington-UMC, using .38 cases with the head (rim) altered prior to the plating of the cases. These are headstamp REM-UMC 38, with the “38” being off-center, since a “38 SPL” bunter, with “SPL” removed, was used. For serial production, a new bunter was made, “REM-UMC 38 AMU” headstamp. Remington rounds, with the exception of a black-case dummy, are usually in nickeled-brass cases, although at least one lot was made with plain, unplated brass.

The .38 AMU was made by three companies, Remington-UMC, Federal, and Western, with the latter calling the cartridge, for whatever reason, the .38 Special Super-Match Mid-Range semi-Rimmed cartridge. You were very perceptive about the rim configuration. The .38 AMU is a semi-rimmed cartridge, not truly rimless.

The headstamps & variations I have are:

FEDERAL 38 AMU - plain brass case.
REM-UMC 38 - nickeled-brass case
REM-UMC 38 - Backened case, one hole in the center of the primer cup
REM-UMC 38 AMU - nickeled brass case
REM-UMC 38 AMU - brass case
REM-UMC 38 AMU - Proof load, full RN Lead bullet which would have required direct insertion into the barrel, as it is too long for the magazines of the .38 AMU Colt pistols
WESTERN 38 SPL SR - plain-brass case, red primer seal

There is also a REM-UMC 38 with a cast-lead wadcutter bullet seated slight out beyond the case mouth, and with the base colored green. I actually have a full box of those. They may just be reloads, but I put one in my collection since the case shows no signs of every being fired. These could be simply someone’s reloads, or perhaps a “first effort” by Remington. I personally believe it is the former, but kept it anyway, just in case.

All of the others, except for the proof load, have a button-nose lead wadcutter bullet seated with the bullet flush with the case mouth. All have nickel primer cups and all have two cannelures on the case. The proof load has a purple base and purple bullet for ID.

Below are three different box labels for this round. I do not have a Federal box, but they are with the Monarch Brand normal art work. I have a picture of the box for the dummy rounds, and it has a wrap-around label lengthwise on the box with no art work other than the Remington and Peters trademarks, one on each side of the printing.

Here are the box labels I have:

Here is a black and white photo of the Federal box, courtesy of my dear, departed friend (RIP) and mentor Otto Witt:

Edited to add picture of Federal Box label, only.

John Moss

I read this http://www.ammo-one.com/38AMU.html which says “a rimmed 38 Special made rimless”. I did not check further, my mistake.
Here is a link to a topic John Moss is mentioning above Colt Model 1911 pistols and the .38 cartridge

Vlad - thanks for posting this. The word “introduced” may be the key to the Wikipedia information about the date of the .38 AMU cartridge. I don’t know if the 1964 National Matches were the first “introduction” of the cartridge or not, but if so, then the use of that word in conjunction with the date 1964 is valid, but is not the date of development. Aside from the aforementioned 1963 article in “The American Rifleman,” I find in my files an article by George Nonte, from the July 1961 Issue of “Shooting times” titled "The .38 AMU; a Semi-Rim Experimental.

Thanks for the link to the earlier forum thread also.


1 Like

To add here is the Federal in color & and two dummy boxes. As the top 's have the same text I’ve just photos both boxes ends & one top.
With Johns photos this should complete the box series, as far s I’m aware…
edited to add one more a Western / Olin variation

38 amu dummy box ends

1 Like

Great photos Pete. It is the first time I have even seen a picture of that Western Box. I am sure that the dummy-round box is the same as the one I have poor, black and white photos of. Thanks for posting!!!


There are two dummy boxes. Both have the same top but different rubber stamps on the ends.

Hi John and Pete.

There was also a .22 short with an odd lighter weight bullet that was part of the project. It obviously didn’t see much use as the rounds are very scarce.
I have a dummy and proof and have seen a ball round. Headstamps are H and Super X.


Pete - I noted that. I had never actually seen either, and the picture I have is only of the top label, as I recall.


Please post pictures of the two rimfires when you can. I had not heard of these.

1 Like

Ditto. Also, Will, what project? 38 AMU had its own handgun to fire only 38 AMU. Was there a special gun to fire those rare .22 shorts?.

The one in your picture (top) does look like more of a rim diameter then my inventory ?
Maybe a fluke ? that did not get the rimmed resized? No idea .

1 Like

I was just checking Erlmeier-Brandt’s book “Handbuch der Pistolen- und Reolver-Patronen,” for their measurements of the rim and head of the .38 AMU cartridge (Page 92, Volume II, Item number 352) and noted that he shows two cartridges in the pictures - Catalog Number 352-1 is the standard flush-seated lead wadcutter while Number 352-2 has what appears from the side view of the cartridge pictured to have the same bullet as my “green-base rounds.” They do not mention any coloration of the cartridge case head, and in their picture, the bullet appears to be slightly deeper seated than on mine, but proportionately, the “button-nose” of the projectile appears to be identical to those in my rounds.

Their measurements are 10.20-10.25 mm (.401" - .403") for the head (rim), and 9.47-9.57 mm (.373" - .377") for what they call the head, but is better described as the base, as it is the portion of the case directly above the extractor-groove bevel. Of course what we often call the diameter of the rim, is actually the diameter of the cartridge head, hence the term “headstamp.” Measurements of about ten rounds from the Remington box, cartridges with the green head, fall within these measurements, although they extend the range very slightly, only about 0.02 mm.

Now I really wonder what those green-base rounds are. They almost certainly would not fit the magazine of the Colt AMU pistols. I wish they had a better description of the cartridges in that book. A close examination of my rounds with the protruding bullet nose would indicate the cases have been in a internally scarred die, probably the size, as it has fairly uniform longitudinal scratches down to the lower case cannelure. One round has a tiny dent, which is similar to the dent too much case lubricant can produce on a cartridge case.

Later, I will examine rounds I KNOW to be factory, and see if they show these scratches. Out of time at the moment.

John M.

What are the rim and body measurements of the ones you have? Are they close to John’s measurements from Erlmeier-Brandt? Thanks,

With regards to the .22 AMU or Super Match Cartridge, see Woodin Vol III, page 445 for description, line drawing and photo of a box. They used an odd 33 grain bullet. When I have an opportunity in the next few days, I will post a photo.


1 Like

Thanks Will,
If I’m reading it right, your H and SUPER X would be from the earlier Olin contracts. The Remington box and U headstamped 33 gr. “Special Match” rounds, are from the 1963-1964 purchase order. It will be interesting to see your Dummy and Proof, and compare it to the later Remington drawing.

I sent a message to an old friend who was a member of the AMU, 20 or so years ago, to see if he has any info, and I will post anything he sends me. I hope the following helps a little.

Here is a bit of history from the m1911.org forum web site:

".38 AMU Cartridge

Back in the late 50’s and early 60’s the Army Advanced Marksmanship Unit, ( now known as the Army Marksmanship or AMU), was concerned with the major problem of proper functioning of the rimmed .38 Special cartridge through converted 1911 pistols. The major problem was feeding- there was a noticeable difference in the position of rounds in the magazine between the first and last rounds. To overcome this problem magazines were modified, feed ramps were polished, and the chambers enlarged to allow the cartridge to ride up the ramp and into the oversized chamber. This oversized chamber caused problems with accuracy.

To alleviate the feed problems Herman Gano, an AMU gunsmith, came up with the ideal of the .38 AMU cartridge. The .38 AMU is basically a .38 Special with a semi-rimmed head, like the .38 Super. When used in appropriate guns, nearly all the feeding problems were eliminated. The first cases were hand made by turning down a .38 Special case in a lathe to remove the rim and form an extraction groove. Later the Army contracted Federal, Winchester-Western and Remington to produce the .38 AMU cartridge.

Colt Industries followed through by producing a conversion kit to be fitted on both the 1911 and Colt .38 Super pistols. The conversion kit consisted of a .38 AMU slide with all the innards, recoil spring, magazine, barrel bushing and a .38 AMU barrel. One interesting note, other than ID markings, there’s no difference between the .38 AMU and .38 Super slide.
strong textThe barrel is unique in that it had only one forward locking lug so the gun wouldn’t lock up too tightly and hinder proper cycling with midrange ammo. The work required to “convert” a pistol to .38 AMU is approximately the same as a full accuracy job. The slide must be fitted to the frame, the barrel must be fitted to the slide, and the barrel lug fitted so it cams with the slide stop pin.

.38 AMU never really took to the shooting crowd for several reasons. There were no empties available for reloading, (most shooters were geared for .38 Special), the conversion kits were somewhat difficult to install by the shooter, the advent of the .38 Special Gold Cup magazine which solved the feeding problem with regular .38 Special wadcutters, and the introduction of the Smith and Wesson 52, an out of the box match gun."

According to Smith & Wesson:
“In 1960, the USArmy Marksmanship Training Unit asked Smith & Wesson to build a pistol similar to the Model 39 that could fire the newly developed .38 AMU cartridge. The result was the Model 52, the most accurate target pistol of its day…”

A S&W 1961 Advert:
Model 52 Pistol
In 1960, the U.S. Army Marksmanship Training Unit asked Smith & Wesson to build a pistol similar to the Model 39 pistol that could fire the newly developed .38 AMU cartridge. The Model 52 pistol was the most accurate target pistol of its day and featured an innovative ball-bushing barrel.”


I got a quick reply from my friend, all he said was [copied verbatum]:
"I will look around for info, but if you ned berass, make it from 9mm Mag brass"

Are there any details on a Smith & Wesson Model 52 actually chambered for the .38 AMU Cartridge? (“In 1960 the US Army Marksmanship Training Unit asked Smith & Wesson to build a pistol similar to the Model 39 that could fire the newly developed .38 AMU cartridge.”) All the material shown refers to the Standard Model 52 chambered for the rimmed .38 Special revolver cartridge.

While likely that a Model 52 S&W in .38 Special WC caliber could use .38 AMU cartridges, I am referring to any with, for example, a breech face actually sized to the semi-rimmed cartridge rather than the full-rimmed .38 Special.

John Moss