OT short chambered barrel

[Fordyce Beals]

I have a Mauser 1896 6.5 x 55 that I sporterised many years ago when they cost $60 or so dollars. The cut down original barrel is very hard on the jacket of my reloaded cartridges such that you can see lead squirting out on the land/grove engraving when the bullet goes through the paper target. With more muzzle velocity all the bullets just blow up and never make it to the target. I tried Barnes monolithic bullets with published data, but had a high pressure case indication on the odd shot, the primer pocket got a lot bigger!

 

Now I have a Midway pre fit short chambered replacement barrel. My question for those gunsmiths with more experience then I have:

 

Can I treat the short chambered barrel as a wild cat and shorten the sizing die to shorten the case to get good headspace and save the extra $150.00 for the finish chamber reamer and go, no go head space gauges?

 

Fordyce (Who's always striving to reduce desires to less than total means)

[Doc Fill 'Em 67797]

That's a good question, I'm in the process of building a '98 Mauser with a Brownell's short-chambered .308 barrel. I think they are supposed to be short chambered about .050 or so, that might be more than the brass can handle and of course you could never use factory-made ammo in it.

[Garrison Joe, SASS #60708]

There's no real guarantee that the short chamber in the new barrel is the right shape or that the neck is right internal diameter. And it's probably cut with a roughing reamer, meaning it will be likely to stick brass because the surface is not finished the way a finishing reamer will do it.

 

If you leave the gun short chambered, you have created a one-of-a-kind wildcat, and

1) it may not work all that well and

2) no one in their right mind would buy it from your or your heirs when you are done with it, at least for anything other than parts.

 

Might as well finish it up right.

 

But, is the original barrel really in bad shape? Or are you overloading the cartridge? The 96 Mauser is not all THAT strong of an action, not a 98 by any means. Getting the existing barrel to work by lapping, or fixing whatever problem it has, is likely to be the cheaper faster route.

 

Good luck, GJ

[Dubious Don #56333]

The 'short chambered' barrel is likely not finish reamed so it will most likely have tool marks that will interfere with the proper extraction of the case. The PROPER way to fit a barrel is once it is installed, use the proper reamer to deepen the shoulder until the bolt closes on a go gauge.

 

Having had some experience with ballistics I would say from your reference to blown primer bockets and clear signs of excess pressute that your problem is less one of a 'bad' barrel and more of an overloaded cartridge. When you take bullets designed for xxx velocity and exceed that, they can and do come apart and in the case of the ones you noticed not making to the target, seen that. I've seen 22-250's and 30-06's with light bullets driven waaayyy fast simply vaporize on the way to the target. Try backing your load off a bit before you pull the barrel.

[Fordyce Beals]

In answer to some of the questions:

 

I played around with a lot of reduced loads and I give up on the original barrel. I bought the Midway A & B pre chambered and threaded barrel, it is in hand. The .050 short chamber has a mirror finish when looked at in direct sun light. How they make and sell these barrels for so little $ reinforces my confidence in American markets.

 

I have the bullet manufactures loading manuals and a scale, this is not the issue

 

“The PROPER way to fit a barrel is once it is installed, use the proper reamer to deepen the shoulder until the bolt closes on a go gauge.”

 

This is what I am trying to penny pinching around.

 

“There's no real guarantee that the short chamber in the new barrel is the right shape or that the neck is right internal diameter.”

 

This is the key issue that I am looking for advice on. Thanks for the discussion!

Fordyce

[Garrison Joe, SASS #60708]

Maybe it's a matter of the pride of doing it yourself, but if you can find a smith already possessing (or willing to rent) the reamer and gauges, he might be able to just to fit the barrel for you and leave bluing and muzzle profiling and all the detail work to you, and save you some of the costs of him re-barreling the gun as a complete job.

 

But, you know that, I'm sure.

 

Good luck, GJ

 

 

BTW - chamber casting the new barrel as it is now, would let you take critical measurements on what "shape" (pun intended) it is in (shoulder angle, shoulder depth, neck diameter and length, freebore length if any).