Ammo Problems - 7.65 Argentine

[Hinnerk]

I was shooting the 1891 Modelo Argentine again yesterday and had a couple of problems:

1) Previously, I had only used PPU ammo in this rifle (a recent purchase) and had no problem with that. Yesterday, I tried some Hornady/Graf cartridges and found that the bolt would only close with great difficulty. I am assuming that this is a problem with the shoulder to head distance being too long. Has anyone else noticed this with said ammo? Could there be any other explanation? I did notice that the face of the head (toward the bolt) to extractor groove distance was a bit thicker in the Hornady/Graf than PPU. That could account for it, I suppose, if the manufacturer formed the shoulder based on the distance to the extractor groove.

2) One round had a very fine pin hole in the primer after firing. Is this an ammo issue or a rifle issue? If the latter, what is the cause and solution?

[Hinnerk]

I took some measurements with a caliper and found that the bullet in the PPU ammo has a max dia. of .311" while the Hornady/Graf is .312". Case length was the same. I couldn't adequately measure the shoulder but by eyeball I could discern no difference.

[TRAP55]

I would chamber one, then see if the bullet or case is marked up. Sounds like you could have ammo with the bullet seated out into the lands.
Check the firing pin protrusion, should be .055 to .065 inches. Check the tip of the FP too, if you pierced a primer, it may have got damaged.

[louie]

Is the Hornady ammo made in Serbia? If so, it's the same as the PPU stuff. I don't think Hornady makes this in the US, but not sure.

[Hinnerk]

I was under the impression that the Hornady was made in the U.S. but I could be wrong. I bought the ammo at a gun show. It is soft point and came in a regular Hornady box (not the newer box as shown on Graf & Sons site) but the cases are stamped Graf. The PPU is FMJ with a smooth curvature to the bullet. The Hornady is more cone shaped with an abrupt transition in curvature at the max diameter point.

I'll have to take TRAP55's suggestion next time I am at the range.

By eye, I see nothing wrong with the firing pin surface but have not yet measured the protrusion distance.

[pacrat]

I was shooting the 1891 Modelo Argentine again yesterday and had a couple of problems:

1) Previously, I had only used PPU ammo in this rifle (a recent purchase) and had no problem with that. Yesterday, I tried some Hornady/Graf cartridges and found that the bolt would only close with great difficulty. I am assuming that this is a problem with the shoulder to head distance being too long. Has anyone else noticed this with said ammo? Could there be any other explanation? I did notice that the face of the head (toward the bolt) to extractor groove distance was a bit thicker in the Hornady/Graf than PPU. That could account for it, I suppose, if the manufacturer formed the shoulder based on the distance to the extractor groove.

2) One round had a very fine pin hole in the primer after firing. Is this an ammo issue or a rifle issue? If the latter, what is the cause and solution?

You cannot "accurately" measure exact >base to datum< of a cartridge aka headspace. Without specific tools which many/most shooters/reloaders don't have.

If you have a set of dial or digital calipers you can make "comparative" >base to datum< measurements between different ammo lots quite simply. Using a 3/8" diameter sleeve long enough to reach from the shoulder past the bullet tip of a loaded round.

Slip the sleeve over the bullet/case neck to the shoulder. Then measure from the base to the end of the sleeve. Subtract the sleeve lenght dimension. Do this to both rounds. Finish measurement of each after subtracting the sleeve is your "comparative" measurement.

Doesn't give exact base to datum of either. But does give exact difference between the two.

JM2c

[Hinnerk]

louie et al.,

Surprise! I bought a further box of Hornady 7.65 Argentine ammo from a LGS today and Lo! and Behold! the cases on these rounds are stamped PPU! The bullets look identical to the stuff in the cases stamped Graf, though. I think that I am going to have to write to Hornady to learn the story behind these lots. Maybe some were made abroad with Hornady bullets (sounds incredible) or some were made with PPU brass (also sounds incredible).

Bullets are 150 gr and look like these:

http://www.hornady.com/store/303-Cal-.312-150-gr-SP/

[huaiqiane]

The Hornady is more cone shaped with an abrupt transition in curvature at the max diameter point.

[MasterChief]

Here is some possibly related information:

http://parallaxscurioandrelicfirearmsforums.yuku.com/reply/50982/history-of-765X54-X53#reply-50982

[Hinnerk]

I received a reply from Hornady and was told that they load this ammunition for Graf & Sons using brass provided to them by Graf and that brass is made by Prvi Partizan. That explains the markings. I haven't figured out the chambering issue, yet, but Hornandy suggested contacting Graf.

[pacrat]

No solid answer from me but a possibility on shoulder issue.

The 7.65 Mauser has 2 different designations. 7.65x53 and 7.65x54. Originally made IIRC as the 7.65x54 Belgian Mauser in 1889. The adopted by the Argentines as the x 53 in 1891.

Since Prvi Partizan ammo is made in Europe. They "may" make the cases to the x54 spec. European Chamber, Ammo, Pressure specs are by CIP. Here it is SAAMI.

You might want to check for CIP chamber and ammo dimensional specs.

just a thought

[knucklehead0202]

I was gonna say, hornady/graf ammo uses the same brass. Sounds like your argy has a tight throat, which is a beautiful thing. Shoot what works in it and if you reload, use .311 bullets. If you don't, send me your brass

[Hinnerk]

I don't currently reload but that is on the (want) "to do" list and so I have been saving my brass. Now that I know that Hornady/Graf brass is actually PPU origin, there is not any good reason to pay a premium for it (as fresh ammo).

I did do some caliper measurements on the cartridges and fired cases using a brass pipe nipple over the bullet end and resting on the shoulder to see how they compared. I did notice that the Hornady ammo measured a few thousands of an inch longer than the PPU but all fired cases were even longer still so that scheme didn't reveal any useful information. Perhaps it is a tight throat issue.

I forgot to bring this rifle to the range today so still have not gotten around to chambering and extracting some rounds for visual clues.

[knucklehead0202]

Sometimes just the shape of the bullet/ogive can make a difference in chambering. I've encountered this with at least one of the chamberings I load for, that even using the same type/weight/diameter bullet, different brands of bullets have a slightly different contour and it does affect where I have to seat them so they don't hit rifling. If the prvi works for you, buy a ton of it. In my experience they make great ammo and the brass is very high quality as well. Enjoy!

[Jarhead]

Reload and you will see how accurate your Mauser can be