Cartridge identification

[ilbob]

So I bought this Mosin rifle and it came with a 50 caliber ammo can full of ammo. Most of it was in boxes or little packages but there was 46 loose cartridges. In looking through them to make sure they were all the same I found one that was different. I think it's a 308 but I'm not sure. The headstamp says B81, R1M1, and 7.62.

I poked around some of the collector sites looking for headstamp markings but didn't find this one. it is probably there I just don't know where or how to look it up.

anyone have any definitive ideas on what it might be

 

[ilbob]

 

[dgod]

7.62 makes it a 30 Caliber, could be .308, coud be 30-06. Can you measure the overall case length? That would help as well.

 

[dgod]

.308 COAL 2.810", 30-06 COAL 3.340

 

[ilbob]

I don't have my calipers handy however it is a rimless cartridge so I'm pretty sure it's not a 30 06.

 

[ants]

... however it is a rimless cartridge so I'm pretty sure it's not a 30 06.

30-06 is rimless.

 

[ants]

South Africa had some weird markings.

The B81 is year 1981 production from their "Factory B", the Pretoria Metal Pressings plant in Kimberly, South Africa.
There were two ammo plants at Pretoria, the original one called Factory A. Obviously, the second one Factory B.
[Factory A was also called A because its previous name was ArmsCor, not to be confused with the Philippine gun manufacturer.]

R1M1. The R refers to the model. The M refers to the mark. This cartridge is Model 1 and Mark 1.
[The S.A. use of R*M* is no different than our M*A*, as in M16A1 rifle.]
I don't know if an R1M1 is 30-06 or 7.62x51, but in 1981 most likely a NATO cartridge.
Measure the length, like dgod told you.

 

[Walkalong]

Taper looks like an .06. Measure the case length and overall length.

 

[Jonesy814]

It would help to have a picture of the whole cartridge