[Rosko Packer]

I'm not sure where to ask this question so I'll start here. I have a friend with a fairly nice sporterized mauser. It is an Argentine of some sort and the reason I don't give all the numbers and writing is that we can't determine the proper cartridge. On the barrel is marked 7.62 M. I don't think this means 7.62 Nato even tho I know at one point some Argentines were converted. 7.65 Arg.Mauser ammo does chamber, but 7.65 is NOT 7.62. I've seen reference to a 7.62 X 53 and some other odd balls. Does anyone out their know what this is? A miss-marked 7.65? An obscure round ? Help

[Snakedriver]

Does it look like this? It's a good chance that it is an "unmarked" 1916 Spanish Mauser like mine that was converted from 7 X 57 to 7.62 NATO. The conversion was quite common. A good gunsmith can make a cast of the chamber and tell you what the dimensions are and thus determine the correct caliber.

[Rosko Packer]

This has a cheeked fairly nice sporter stock. It is not 7.62 Nato. The round will chamber, but the bolt face doesn't seem right, almost like the cartridge head is not correct. The markings for caliber say 7.62 M. The barrel has the "steps" left on some milt barrels. The rifle (at least action) was made by Mauser and is the Argentine type (no rear lug etc.) The 7.65 Arg ammo from Seller + B will chamber and I believe would fire. The difference in bullet size from 7.62 to 7.65 should cause some pressure problems? I don't know if this is a rare weird rifle, or miss-marked, or just some odd chambering that can't be found.

[trip286]

Originally Posted by Rosko Packer

This has a cheeked fairly nice sporter stock. It is not 7.62 Nato. The round will chamber, but the bolt face doesn't seem right, almost like the cartridge head is not correct. The markings for caliber say 7.62 M. The barrel has the "steps" left on some milt barrels. The rifle (at least action) was made by Mauser and is the Argentine type (no rear lug etc.) The 7.65 Arg ammo from Seller + B will chamber and I believe would fire. The difference in bullet size from 7.62 to 7.65 should cause some pressure problems? I don't know if this is a rare weird rifle, or miss-marked, or just some odd chambering that can't be found.

If you can't figure out the chambering get it cast by a smith. Sure something will fire through it, but is it worth ruining the rifle? or your life?

No, just be safe and have it checked out, unless you find someone that can tell you FOR SURE what it shoots.

[303tom]

Take it to a smith!

[c3shooter]

As said- get a chamber casting. Product called Cerrosafe. You plug the bore- patches will work, melt the Cerro, pour into the chamber. After a stated period of time, you can pop out the casting. After another stated period of time, you can mike the casting. That is the ONLY guarantee of the cartridge that gun is chambered for.

[jpattersonnh]

Many of the Argentine Mausers were re-barreled for .30-06, 7.62. After WWII 90% were converted.

[Rex in OTZ]

Instead of rebarreling importers reamed the chambers to 30-06 so you basicly had .311-06's

I'd also say like the other poster get a chamber casting as your best bet in finding out what you have.

7.65x53 (7.65 Argentine / 7.65 Belgian) and 7.65x53R

Question about ammo for my Mauser 1909 Argentine - THR

It was easy figuring my (1900 dated) 1891 DWM mauser in 7.65 Arg, they dont readily convert to much else unless you rebarrel, the 1891 is not as strong as the model 98 mauser action the Arg 1909 Arg is model'd after.

[jpattersonnh]

The Argentines re-barreled them, importers just changed out the stocks. Herters did this quite often years ago as did others. There are quite a few that still have 7.65 bores, which seem to shoot .308 bullets very well considering. .30-06 was used in the U.S. 7.62 was used by countries that used metric calibers at the time.

[superc]

The strange thing is that the bolt won't fit right on a 7.62 Nato. That cartridge is essentially a shortened .30-06, and when the U.S. invented the .30-06 they kept Mauser rim dimensions (because the Springfield was a plagarizing of the Mauser 1898). Almost all Mauser cartridges, 7mm, 8mm, etc. have the same head diameter and extractor groove. Really simplifies things at the factory.

I have a suspicion that while your rifle may be a bolt action, it may not be an actual Mauser design. As said above, get some cerrosafe and take the casting to a qualified gun smith.