7.62x51 NATO or 7.65x53 Belgian/Argentine?

sean69

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Just picked up a sweet little peruvian carbine in 7.65x53 Belgian/Argentine.

Or so I thought; knowing that a lot of these SA Mausers were converted to .30-06 I decided to verify.

- didn't even come close to chambering on a .30-06 case, ok.
- chamberd on a 7.62x53 dummy, BUT the rifling scratched the hell out of the bullet.
- pulled the bullet and measured = .308 ~ hmm
- tried chambering with a .312 bullet [correct for the caliber] not even close, at 2.80 COAL [0.19 short of max] the bullet got pushed back into the cartridge by about to 0.2!!
- decided to slug the barrel, a solid .310/.309 [WTF?]
- placed some transfer color on the neck of an argentine case, got a very clear transfer all around the rim of the neck [the fat part] but no transfer at all on the shoulder. hmmm

So looking at the drawings of the 7.62x53 and a .308 winchester, pretty darned close a .308 win should chamber in the argentine and vise-versa. the difference in the angle of the case shoulders explains the transfer color only appearing around the rim.

But .308 win is not 7.62 NATO.

easy enough to find the Argentine drawings: https://en.wikipedia.org/wiki/File:7.65%C3%9753mm_Argentine.png

can't seem to find the NATO drawings :(


So, "WTF" could this thing have been re-chambered to 7.62x51 NATO and NOT marked? [because it's not]
The dimensions of the slug [0.310] and the correct bullet [0.312] and not being able to chamber a full length Argentine, make me think using the 0.312 bullets is going to be unsafe.

Dunno, thoughts anyone?

-sean
 
It's my understanding .308win is the same as 7.62x51 NATO in dimensions....but I am fairly new to the .308 game.
 
No markings on barrel but this, not sure if it is correct/original:

20151226_123523.jpg



indexing mark on receiver, but not barrel.

20151226_123532.jpg



Looks to be rebarreled?
 
What exactly are the tolerances on bore diameter [in the grooves] to maximum bullet diameter?

I see my reloading manual shows 7.62x39 as a .308 or .310, .303 Brit shows .310/.312
 
I agree with those who say to cast the chamber.

As for the .309-.310 dimension, there are a few ways you can go. You'd be surprised how many .30-06s and .308s actually slug out to .309 or .3095. You can shoot those with .308 bullets, no problem -- just some brands of bullet might give more accuracy than others. (Here is where Hornady bullets shine because they are soft and tend to "bump up" in slightly larger bores.)

If you want to be super-precise, you can order a Lee .309 Cast Bullet Sizing Die. It costs about $25. You can then buy .303 jacketed bullets, lube them up and run them through this die on your press. Instant .309 bullets with perfect uniformity. The force involved to do this is about the same as resizing brass.

Your biggest challenge is going to be to figure out the dimensions of your chamber so you know what cartridge to use. The .308 and the Belgian/Argentine case are quite different and not interchangeable.
 
I agree with those who say to cast the chamber.

As for the .309-.310 dimension, there are a few ways you can go. You'd be surprised how many .30-06s and .308s actually slug out to .309 or .3095. You can shoot those with .308 bullets, no problem -- just some brands of bullet might give more accuracy than others. (Here is where Hornady bullets shine because they are soft and tend to "bump up" in slightly larger bores.)

If you want to be super-precise, you can order a Lee .309 Cast Bullet Sizing Die. It costs about $25. You can then buy .303 jacketed bullets, lube them up and run them through this die on your press. Instant .309 bullets with perfect uniformity. The force involved to do this is about the same as resizing brass.

Your biggest challenge is going to be to figure out the dimensions of your chamber so you know what cartridge to use. The .308 and the Belgian/Argentine case are quite different and not interchangeable.


Slugged my 1909 Argentine [7.65x53 for sure] it's bore slugs out to .310/.3095 as well.

The suggested COAL in the Hornady data for this bullet says 2.815, if I make a dummy at the max length [2.990]: the Argentine will push that bullet back to 2.94, the Peruvian will push it back to 2.76 a difference of 0.575. hum.

looking closer at the case dimensions, the .308/7.62 are fully 5mm shorter from base to the shoulder. zero chance of chambering a 7.65x53 in either of them. [my bad]


I think the chamber dimensions are right. just a question of the bullet diameter, not sure I have shot .312s through the Argentine, .310 for sure, .3105 for sure, not sure about anything bigger.
 
I'm referring to a 32-20 hard cast bullet tapped into the lead with a brass rod and tapped back out...not a proper 'slugging of the bbl. The (virgin) slug on my digital caliper is .311; after a ' Just the tip ' slugging, comes out at .304 x .311. But didn't even get marked by the grooves. I reloaded mine with some .3109 dia FMJ's and found it threw the odd flier. Like a real flier...a " Did I just flinch badly? " flier.
Your's is a 1935; correct, backwards safety lever?
I'm suspecting these carbines have pretty generous bores. I'd love to say that I'll cast off a PL .31 caliber ball and clean / grease the bore well and slug it proper...but probably not going to get to it til Spring. But they are a generously proportioned bore.
Don't know that this helps, but that's just my input.
Good Luck.

Edit, just ran a piece of homemade buckshot through it. There was a round sitting right here. At .311 it shows no scrape marks, it's big bored...
 
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Regarding your barrel - from several references on Internet, a "crown over ELG in an oval" is a proof mark from Leige in Belgium. From Ball's "Mauser Military Rifles of the World 5th edition, Peru "short rifles" (and I am assuming you have a large ring 98, rather than an earlier 93/4 were Czech VZ24, VZ 32 and then Model 1935 short rifle - the latter from FN in Belgium. If your rifle has a "backward" safety - fire it with the safety lever to the right - then you probably have a rifle and barrel made in Belgium in late 1930's. It says many were converted to 30-06 but were marked if converted.
 
Regarding your barrel - from several references on Internet, a "crown over ELG in an oval" is a proof mark from Leige in Belgium. From Ball's "Mauser Military Rifles of the World 5th edition, Peru "short rifles" (and I am assuming you have a large ring 98, rather than an earlier 93/4 were Czech VZ24, VZ 32 and then Model 1935 short rifle - the latter from FN in Belgium. If your rifle has a "backward" safety - fire it with the safety lever to the right - then you probably have a rifle and barrel made in Belgium in late 1930's. It says many were converted to 30-06 but were marked if converted.



it is a 1935 peruvian carbine... 17.5" barrel. not the short. it is not in rhe mauser book. (not my edition anyway)

yes to the reversed safety.

tokguy.. no pics. sounds like you tried to post??. and what are you reloading for. didnt see that mentioned.
 
Oh, I've the identical carbine.Lil Mulita the cadets called them.
Very cool, and if your's is anything like mine , I'd go with at least .312 diameter bullets.
Somewhat rare and quite handy to use.
Thread started search me and you'll see mine
 
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