Cartridige ID need help

[NRFJR]

Hello, Not sure if this is the place to ask this but I'm sure some one will tell me where to go. I am not a cartridge collector other than a few that have been given to me or something I have a firearm for. My father gave me a shoe box full of old cases and loaded ammo most of it was .30 carbine 30-30 30-06 and so on I found a loaded round that I though to bo 303 brit. I put it on the shelf with my verry small colection next to the 303 brit cartridge that I had, after looking at them side by side they were just a little different, The cartridge has a head stamp that reads, U, a dimond shape, 1943, VII. The OAL is 77.02mm, bullet diameter is 7.92mm, case OAL is 56.04, Rim diameter is 13.32, now what got me was that the primer size it is realy big, diameter is 6.42 it looks to be a copper cup. Thanks for any information that you could give me I would just like to be able to label it and know what I have. Thanks

 

[jstein650]

A pic would help, but that's about right for Berdan primed .303, which they all were then. South African Mint, Pretoria used a "U" in the headstamp, diamond shape = Kimberly factory, and they made a lot of .303 And, yes, their primers do look unusually large.

 

[NRFJR]

Thanks for the info. The cartridge has a very sharp and short sholder unlike the factory 303 brit that I have, I will attempt to take and upload a picture or two.

 

[NRFJR]

Here are some pictures. I hope they help. Thanks for the help. The one on the left has the U head stamp if that helps any.

 

[jstein650]

Most unfired brass that I have is closer to the one the left, but my fired rounds are considerably more filled out that the one on the right. As long as the critical dimensions aren't oversized, they still shoot fine. The actual chambers of most Enfields are considerably more generous than the case, save for the throat itself. They did it that way to make up for good feeding even if very dirty and possibly slightly swelled ammo in the sweltering heat.

 

[303tom]

That is a .303............
U or SAM
South African Mint, Pretoria, South Africa... U code from 1939 - 1961 and SAM 1962 onwards. (When U is used with a diamond this represents the Kimberley factory... B, BCMK7, TRGMK2, Semi AP (F Mk 1), Jacketed soft point sporting.

http://www.dave-cushman.net/shot/303headstamps.html

The one on the left might be a Improved.........

 

[dagger dog]

Yeah, that shoulder looks like the double radius of a Weatherby cartridge.

Never heard of a 303 British Weatherby Improved !

 

[jstein650]

This is how my rounds look. On the left, typical Mk VII military, the right my neck sized reload.