Bulging Brass

[mdwest]

I found a sporter'd M98 in 30-06 on the cheap that I picked up intending on either doing a barrel swap or a JES rebore job on to turn it into a 9.3x62... But took it to the range yesterday to put a few rounds through it and see how it performed before making a final decision (thought I might just keep it a 30-06 and spend the $$ on sprucing it up a bit rather than on barrel/bore work)...

I put about 10 rounds of federal blue box (150 gr) down range with it and then shifted to a couple of rounds of Hornady "whitetail" 150gr before I noticed a problem...

While it groups well (the cheap federal stuff was putting about 1.25" groups together and the Hornday cheap stuff put 2 rounds about 1" apart before I stopped shooting).. it feeds well (zero problems), extracts well (zero problems), etc..

The brass is coming out consistently distorted (see below).. a short distance down from the neck the brass bulges a slight bit, but only around 50% of the case (the bulge line isnt on the other side).. and there is a distinct bulge at the foot near the rim that does go all the way around the brass...

It would appear the gun has a bad chamber? (now I know why it was sold for a song I suppose)... but with the consistent and reasonably accurate groups with cheap ammo, Im wondering if something else is going on that Im not seeing/understanding?

If the chamber is indeed bad, that pretty much solidifies the deal.. I'll ship it off to JES for a rebore and rechamber to 9.3x62 (I'd thought about 35 Whelen as well.. but if the -06 chamber is bad, I dont think reboring to .35 whelen would help unless they did quite a bit of work to cut a couple of MM off the current chamber, re-tap the threads, and then re-bored the chamber as well (I think it might be a good bit more work than just going 9.3x62)...

Anyone have any thoughts or ideas about what might be going on (other than a really poorly cut 30-06 chamber)?

 

[BourbonTrail]

That looks like a bad chamber to me (or someone tried a re-chamber and didn’t complete).

 

[Inline6]

Can't answer to the why, what can be said. You might as well go on your original path, no way to fix it. Personally would not shoot it any more in current condition.

 

[mdwest]

I agree.. I have no way of fixing it myself... its going to have to go to a smith or JES...

Im just wondering (and probably no way to tell without JES or a smith evaluating it in person) if its even a candidate for a rebore.. or if I need to just find a new barrel... the bulge near the top of the case doesn't concern me too much.. the dimensions of the 9.3x62 are larger than the 30-06 by a hair (width wise), so I think that would work out fine..

Its the bulge at the bottom that concerns me.. that seems a bit excessive.. and might indicate that the chamber is too loose even for the 9.3 already and that reboring wouldn't be a decent option..

 

[375er]

Toss that barrel and make what you want.

 

[TroyF]

First I would try the 30 Gibbs reamer I have hehe, then rebarrel if that doesn't satisfy. I think that barrel is junk other then to use for say a 300 mag. Don't think the chamber would clean up even if the barrel was set back a few threads after a rebore. Don't want to have all that work done and still be to fat just above the web.

 

[mdwest]

I think that barrel is junk other then to use for say a 300 mag.

I hadnt thought about a 300 WM.. that might could work.. With head spacing off the belt of a 300 WM, and the slightly larger chamber of a 300WM.. That might be the best overall solution (although I may still just scrap the rebore idea, call shilen and order a 9.3x62 barrel.. and be done with it.. Im pretty sure the barrel on the gun currently isn't anything special..

 

[TroyF]

I'm waiting for Shaw to make more9.3x62 barrel they had the a month or so ago, I wanted to order one but to many bills then. Of course soon as I had the money they sold out. I'm waiting on a 6mm ARC ar-15 now.

 

[Nhoro]

Do you think it could be dirt or some kind of carbon ring in the chamber just in front of that bulge ? Sounds like you need to take a cast of the chamber and see what that looks like or maybe a bore scope might show up the problem.

Maybe also cut the brass lengthwise but 2 types of brass kinda rules that out. I am thinking someone messed up the chamfering or damaged the chamber somehow and polished out the evidence. Maybe you can measure the brass to see how bad the bulge is in the chamber and then see if it can be chambered up to win mag. SAAMI specs for brass and Chambers are available on the net so you can compare the different options.

 

[Inline6]

I agree.. I have no way of fixing it myself... its going to have to go to a smith or JES...

Im just wondering (and probably no way to tell without JES or a smith evaluating it in person) if its even a candidate for a rebore.. or if I need to just find a new barrel... the bulge near the top of the case doesn't concern me too much.. the dimensions of the 9.3x62 are larger than the 30-06 by a hair (width wise), so I think that would work out fine..

Its the bulge at the bottom that concerns me.. that seems a bit excessive.. and might indicate that the chamber is too loose even for the 9.3 already and that reboring wouldn't be a decent option..

Measure the brass at the bulge, if it is bigger than 9.3x62 you have your answer. 300wm might work, you will then have to do something with the bolt head.

 

[Boyd Brooks]

I re-chambered a Husqvarna commercial Mauser in 30-06 to 308 Norma Mag. It shoots 1” groups at 100 yards. Norma makes ammo for it, as well as I use 338 win mag brass to make target loads.

 

[Inline6]

Looking at the print for an 06 to 9.3X62, don't see it working they are to close to the same dimension. Toss the barrel and start over no reason to waste time and money IMHO.

 

[Hogpatrol]

Are you absolutely sure it's a 30-06. It looks like it may be another cartridge/caliber. I'd do a chamber cast to and go from there.

 

[CoElkHunter]

Almost looks like a botched '06 Ackley Improved chamber job?

 

[PHOENIX PHIL]

Perhaps I’m giving up too quickly…..but it seems 4th and long……punt! Start over with new barrel.

 

[CoElkHunter]

I re-chambered a Husqvarna commercial Mauser in 30-06 to 308 Norma Mag. It shoots 1” groups at 100 yards. Norma makes ammo for it, as well as I use 338 win mag brass to make target loads.

Wish we could find either .308 Norma or ANY .338WM brass here? If you do find it, you have to take out a small loan to buy it. LOL

 

[Berettaco]

Agree with the chamber cast - then see what you’re working with.

 

[shootist~]

Rebarreling to 9.3x62 or 35 W gets my vote.

 

[Wyatt Smith]

I am on the re barrel team. Unless you want a 9.3x64 that would be neat.

 

[CoElkHunter]

My vote is to sell it on Gunjoker with full disclosure as to the problem your having with it. Just put "rare" or "scarce" somewhere in the description and one of the moronic buyers with more money than common sense (and there's MANY) on there will buy it. You could still probably get twice what you paid for it. LOL