UMC .25-20 headstamps


Hi everyone,
This is my first post. So, I have been trying to categorize UMC head stamps, but can find almost no information regarding .25-20 head stamps. There are a variety of different .25-20 cartridges produced by UMC: Single shot, Marlin, Winchester, Mar. & Win H.V… So my question is: does anyone have any UMC .25-20 head stamps they could photograph and share (also with any information you have on the cartridge) on the forum?


Hi Maynard,
This Single shot is all I could find.

UMC 25-20 hsUMC 25-20 SS pro


UMC box and contents:


Thank you for the responses–it is greatly appreciated.


You probably already know, the Smokeless load has the case cannelure, as pictured on the box.



Yes, thanks Dan. The interesting thing about the cartridges in that box is that they appear to be loaded with copper No. 6 primers rather than No. 6 1/2 brass primers. The single shot cartridges with metal cased bullets are listed in the UMC catalogs until 1910 with the 6 1/2 primer. The first REM-UMC catalogs list the cartridge with a No. 6 primer. However, the box appears older than any REM-UMC era box. I wonder if UMC just loaded the cartridges with No. 6 primers since No. 6 and 6 1/2 were interchangeable. A mystery to me. Does anyone know when the 25-20 Stevens smokeless was introduced? I see it listed in the 1896 catalog, but I can’t find it in the 1895 catalog,


No idea on the primers Maynard, but I did find one WCF.
25-20 WCF hs25-20 WCF pro


Here is what the UMC Factory Daily Log has to say about
25-20 rounds and primers:

,25-20 Center fire smokeless:
October, 1895. Commenced manufacture of this round, using
6-1/2 primer.
November 1909: Changed to #6 .018" copper primer

.25-20 Marlin:
September 1894. Commenced manufacture. (handwriting not
clear on the first figure of the primer size and appears to be “1-1/2"
primer. later comments led me to believe that the number was actually
February 1912. Changed to #6-.024” primer.
May 1912. Returned to #6-.018” copper primer for smokeless and Lesmok
shells. (This is the entry that leads me to believe the first primer was 6-1/2,
not 1-1/2).

.25-20 Marlin Smokeless
March 1895. Began making these with 6-1/2 primer.
October 1909. Changed to #6-.018" copper primer.

.25-20 High Velocity
May 1903. Commenced making these with 6-1/2 primer.
October 1909. Changed to #6-.019" copper primer.
January 1910. Changed back to 6-1/2 Brass primer.

These were all the entries regarding primers and cartridges
designated .25-20 I could find. The names of the cartridges
are exactly as written in the log. The entries of themselves
are not exact quotations, simply my own report of what the Log
said about primers. The entries were too long, covering other
facets of manufacturing, to reproduce here considering the
question asked.

Hope this is of some help.

John Moss


@Dan Thank you for the great pictures.
@JohnMoss Thanks for the information on the primers–it is tremendously helpful.

Does anyone know if UMC used specific headstamps for each version of the 25-20 cartridge? For example: Did UMC ever use the headstamp “U.M.C. .25-20 MAR.”, “U.M.C. .25-20 W.C.F.”, "U.M.C. .25-20 H.V.? It appears that a few catalogs depict these headstamps, but I know that the catalog drawings can be misleading.
Also, does anyone know of a 25-20 with the “SH” stamp?
Thanks in advance.


Yes i have some of those loadings you ask for i just tried to transfer some pics but did not manageI have
a small collection of 25-20 plus 3 rounds of the single shot let me know wich ones you are interested
in particular and i will look for them.


Hi Sherryl,
Thanks for the reply. I am interested in seeing any loads with additional script like “U.M.C. .25-20 MAR.” and any loads headstamped with “U.M.C. .25-20.” which have a U stamped on the primer.


OK. Thanks for ringing a bell, but under Marlin, I only found Peters. (3 MAR and 2 MARLIN).
I found this old SH list also. When Pete gets time, He will show us what is really available, and probably what is not!



Hi Dan,
That is a great list. Thanks for confirming that a “U.M.C. S .25-20. H” headstamp does not exist.


Maynard, This does not confirm that, but what was known at the time. It looks like it might be one of Frank W’s, lists, and others may have showed up. But a place to start!



Dan, it certainly is a place to start–and definitely corroborates with the other bits of information that are available. Thanks.



@krag56 Great pictures; seeing those head stamps is very helpful. Thank you for showing them.

The only head stamps I am still wondering about are:
(U.M.C. .25-20 MAR.)
(U.M.C. 25-20 MARLIN)
(U.M.C. .25-20 W.C.F.)
I believe these stamps were used sometime between 1899 and 1906 (when UMC listed the Marlin and Winchester as separate cartridges), meaning they should use No. 6 1/2 brass primers if they are smokeless loads, or No. 1 1/2 brass primers if they are black powder loads. If anyone has a picture of any of these head stamps I would love to see it. Thanks.


I have a few here that may be of interest to you even you did not request them
UMC 25-20 Marlin brass primer lead bullet
REM-UMC 25-20 WIN nickel primer copper lead tipped bullet
REM-UMC 25-20 Nickel primer lead bullet
U.S.C.Co 25-20 H.V. nickel berdan primer
U.S.C.Co 25-20 copper primer with monogramm Nickel plated bullet
U.S.C.Co 25-20 nickel berdan primer nickel plated bullet lead soft point


Thank you for the information, sherryl.


U.S.C.Co 25-20 with Berdan ??? primer