6.5x57mm AI question

[OldBrett]

Hello,

New here, have a question about 6.5x57mm. I got one on a Yugo M24/47 from my brother-in-law. I bought some factory ammo but when i tried to chamber one the bolt would only go down about 1/4 of the way. When I pulled the action/barrel out of the stock '6.5x57 Acl. Imp.' was stamped on the barrel.

So I have a rare version of a rare gun that I'll have to handload for, no problem. The problem is I can't find a definitive way to form the AI brass.

Any help?

Brett

 

[lancetkenyon]

AI (or "Ackley Imp 40°") should be a crush fit with virgin brass in the parent case.

You should be able to take virgin 7x57 brass, neck down to 6.5mm, and fire form to your "AI" chamber. Just remember, when you neck down from 7mm to 6.5mm, the brass is probably slightly lengthening at the case mouth. So that is why you are feeling a lot of resistance when closing the bolt. Crush fit plus slightly longer than virgin length brass to start with.

Also, 7x57 case Length is 2.235". 6.5x57 case length is 2.232". So depending on your virgin brass length, this could be making a difference too.

 

[OldBrett]

Thanks, I reloaded with my dad for years but fire forming never came up. Any links to instructions?

Sorry if this has been discussed before. I've spent some time looking around and didn't find the 'how'.

 

[FEENIX]

Thanks, I reloaded with my dad for years but fire forming never came up. Any links to instructions?

Sorry if this has been discussed before. I've spent some time looking around and didn't find the 'how'.

Brett,

Welcome to LRH, and enjoy!

Do you have the dies for it? There are a few ways to fire-form, i.e., the COW method and hydraulic forming die. I have used both, and there are a few on YouTube.

 

[OldBrett]

Thanks,

I have dies for vanilla 6.5x57, 4 boxes of factory rounds and a gun chambered for 6.5x57 AI. I'm looking for the best way to form casings for the AI.

 

[VinceMule]

Clean the chamber, maybe some grit down in the shoulder area reducing headspace.

The gunsmith may have set the headspace up with a Short Headspace length. -.004 is normal, but many will headspace -.006-.-008, and it sounds like this is what you are dealing with. You may have to pull the bullets in the factory ammo and bump the shoulders back just a tad where you get a "firm" feel on closing the bolt, and keep the bolt lugs lubed.

 

[epoletna]

I believe your Yugo is a controlled round feed, meaning the round must be fed from the magazine. Otherwise, the extractor will not snap over the rim, and the. bolt won't close. Could this be the problem you're experiencing?

As for fireforming, before you get to that stage you might consider taking a cast of your chamber to be sure it is what you think it is. Lots of people use Cerrosafe, which is an easy job. I use a combination of sulfur and powdered graphite. Oil your chamber and barrel, plug the barrel with a cleaning patch, heat up some casting medium, pour in chamber, let it harden, then push it out from muzzle. If you go the sulfur route, heat it gently -- sulfur burns and will smell up your house/garage.

Once you're sure it is an AI chamber, you can generally fire commercial rounds, or slightly reduced loads , and they will expand to fit the chamber. Perhaps not fully on the first shot, but probably over two shots.

Or you can go with a light load of faster-burning powder, a small toilet paper wad, then cream of wheat (COW) topped with another toilet paper wad. It is noisy, so don't do it in town. That will blow the case out most of the way.

 

[FEENIX]

Thanks,

I have dies for vanilla 6.5x57, 4 boxes of factory rounds and a gun chambered for 6.5x57 AI. I'm looking for the best way to form casings for the AI.

If your rifle is chambered to AI, as @lancetkenyon noted, you should be able to fire your loaded factory ammo. Ackley designed his AIs to shoot the parent cartridge, which is the easiest and most economical way to fireform your brass. When you have those brass fire-formed from your rifle's chamber, you will need to decide how to go about loading for 6.5x57 AI. Should you have an AI die made or buy (if available)? This could get costly. Or use another means?

For fire-forming a virgin brass, as I previously noted, you can do the COW method,



Or with a hydraulic forming die (additional cost).



Good luck!

 

[lancetkenyon]

Thanks,

I have dies for vanilla 6.5x57, 4 boxes of factory rounds and a gun chambered for 6.5x57 AI. I'm looking for the best way to form casings for the AI.

Depending on the bullet in your factory ammo, that might be your limiting factor too. If they are a big round nose bellut, you could be engaging the lands of the bore before you get the bolt closed. When you pulled out the round you attempted to chamber, could you see some scarring on the bullet from the lands in the throat? Might be as simple as seating the bullet a bit deeper to push them away from the lands if this is the case.

Looking at some of the Sellier & Bellot and PPU ammo offerings, this could be some of the issue.

If you can get the bolt to close, chamber a round and go fire it. It will form to the AI chamber.

You will get something like this when done. This is .260 Rem to .260AI, but same principal. Mine is a crush fit too. Definitely feel the bolt face draging on the case head. Loaded parent case round goes in, BANG, empty comes out reformed. Since you have factory ammo, this is the easy button as long as you can get the bolt to close.

Fire forming can still be plenty accurate.

 

[OldBrett]

Clean - check, was working on that before, now its the cleanest gun i have

I used a sharpie on a factory load and tried to chamber it and the wear marks don't indicate a single rub spot, I'll try a couple more once the steel is back in the wood

Next step is to pull a bullet from the factory load and see if just the shell will chamber....after that we'll see

Thanks everyone,

Brett

 

[OldBrett]

Thanks for the input all, it helped a lot...I pulled a bullet and tried the crush fit again and was able to chamber the empty cartridge, it just took a lot more crushing than i expected, but the results look good, now to crush the rest of a box and go shoot

Brett

 

[OldBrett]

The gun in question. Yugoslav M24/47 in a 6.5x57mm AI. It was one of the last guns my dad built so lots of sentimental value, looking forward to shooting it.

BTW, I never introduced myself, I'm Brett. My wife and I are 60 and retired living in eastern Washington. I prefer older wooden guns in old school calibers.

un

 

[Justice1327]

The gun in question. Yugoslav M24/47 in a 6.5x57mm AI. It was one of the last guns my dad built so lots of sentimental value, looking forward to shooting it.

BTW, I never introduced myself, I'm Brett. My wife and I are 60 and retired living in eastern Washington. I prefer older wooden guns in old school calibers.

View attachment 559071un

Beautiful Rifle!

 

[epoletna]

pretty stock -- did he do that too? Is it laminated pistol grip and cheekpiece on original military stock? Well done.