"U" marked Remington Primers

I did a short search but when you include the words “primer” or “Remington” in the search title you get a lot more hits than you care to look through.

So, can anyone give me a short and sweet meaning of the different Remington primers with the impressed “U”.

U underlined
Small U
Large U
Any others?


Ray–I can provide some of the answers based on the catalog entries. I can give you dates of use and the intended use for the different primers, but not tonight. I’m too tired. I’ll do it tomorrow. In general, any primer with a “U” was for Smokeless Powder.


I’ll look for you tomorrow. Get a good night’s sleep. I’ll be getting my 12 hours, as usual.


Ray–This won’t address all of your questions, but it should be of some help. The primers were domed until about 1924 when the flat primer was introduced.

[color=#FF0000]The next two pages are from the 1911-12 catalog.[/color]

[color=#FF0000]From the 1918 catalog.[/color]

[color=#FF0000]From the 1923 catalog. I don’t have the 1921 catalog, but the nickled primer was introduced in 1921.[/color]

[color=#FF0000]From the 1930 catalog. This was the last catalog to list Primers as a separate group.[/color]

Thanks Ron. I can’t ask for much better information than that. It’ll take me a while to digest it and I’ll get back if I have any questions.


Ron and Ray…

Remington loaded flat nickeled primers ( no “U” ) in the .30 Krag 156 gr Lead Bullet Guard Loads made for the Navy in 1918, headstamp R A 18…and…Flat copper primers with and without “R” in 1917 and 1918 production of Paper Bullet Blanks and Ball cartridges, headstamps R A 17 and R A 18, so they were using flat primers well before 1924…


Randy–Yes, I was aware of the cartridges you mentioned as using flat primers before 1924 on those military loads. However, I will still hold to the “about 1924” for commercial loads in general. If there is evidence of the use of flat primers by Remington before this on commercial loads, I would like to see it. I do not have any catalogs showing primers from 1924-1928, so could be wrong.

Ron - Randy

I had several 30-40 Krag UMC cartridges that I thought were commercial that had the flat copper primer with large U underlined. I’d almost bet they were pre-1924 but I don’t really know and they are one of the reasons I asked this question.

I also have several UMC 9 07 cartridges with the large U underlined, flat. These are obviously contract rounds made by UMC.

I also have a REM-UMC 1906 Match cartridge that has a large U, not underlined, flat, that appears to be tinned rather than nickeled. That cartridge is a 1921 Palma/Olympic Match.

Ray–Watrous in his notes on Winchester primers mentions the use of flat primers at least as early as 1900 on an experimental basis, but found no advantage and kept the oval primer until the early 1920’s. Perhaps Remington likewise experimented with flat primers earlier also. Winchester used flat primers on the .30 U.S.G, 6mm Lee-Navy and the .30 Govt, M.03. I did not address the U.M.C. primers originally because the original question asked only about Rem-UMC.


U M C 9 07 ???..or 5 07 maybe ?

Yes, UMC used flat brass and copper primers extensively…so did Winchester, not just experimentally, but in production…many many W.R.A.CO. 30 U.S.G. cartridges used flat brass primers, and many of them were double cup, like the Protected Primer but lacking the hole in the center of the brass cup…


Randy - You’re right. 5 07. I gave a bunch of them to you didn’t I? I have only a few empty cases left, with cracked necks, so the bullet and powder are gone.