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View Full Version : barrel replacement on a 1903???


saands
March 3, 2007, 05:59 PM
I know the 1903 is a cousin of the Mauser action, but I was wondering what is involved with changing a barrel out on an 03a3. Is it the same as the Mauser? Simpler? More complicated?

Thanks,
Saands

Dfariswheel
March 3, 2007, 08:17 PM
Change out is very similar to the Mauser.

saands
March 3, 2007, 08:30 PM
Thanks ... the current CMP 03's sound like they are likely candidates for a replacement, so I wanted to get an idea of what I might be in for. Do you use a similar barrel wrench/action vise?

TIA,

Saands

James K
March 3, 2007, 09:48 PM
Yes, but there may be problems. Is the new barrel to be a GI replacement barrel or a new sporter barrel? If the former, things are fairly simple. Just use the existing draw line and fixed base to line things up, then (if a new barrel) run in the finishing reamer until the GO headspace gauge fits.

If the "new" barrel is an old military barrel, you may have a problem and have to get good headspace by trying a variety of bolts. With luck, things will work out without too much trouble.

With a new sporter barrel, things are tougher. You have to run the barrel in, bring it up to just about the right torque, then mark it, remove it and cut the extractor slot. Then reinstall it, bring it up tight, and finish ream the chamber to get the headspace right. This is assuming you don't want to reinstall the military sights; if you do, you will have to machine the barrel to size at the right places to do that, plus doing the drilling and slotting that are necessary.

The Mauser 98 is a lot simpler because the receiver has an inner collar that takes care of the extractor cut and allows the barrel to be flat at the back. Then it is only a matter of keeping the collar contact and the shoulder contact even. Plus, the sights on the Mauser were put on after the barrel was installed, where the sights on the M1903 were installed and the extractor cut made before the barrel was screwed into the receiver.

Jim

saands
March 3, 2007, 11:12 PM
Jim,

As usual you are a veritable fountain of knowledge ... thanks! This is exactly the info that I was looking for. I will hope that the luck of the draw goes my way and that the existing bbl is a keeper, but either way, this one will be (and stay) a GI type rifle, so it won't get as complicated as the sporter scenario sounds. Are these barrels usually REALLY on there like some of the old Mausers are? Are there any tricks in getting them to come off? While I'm at it, does Kuhnhausen
have a 1903 Shop Manual?

Thanks again,

Saands

Harry Bonar
March 4, 2007, 05:18 PM
Sir:
In regard to getting the bbl. off sometimes a lathe or hacksaw cut just forward of the action in the old bbl. will relieve pressure on the joint and you can turn it right off.

Be sure to follow Jim's directions!
Harry B.

James K
March 4, 2007, 08:49 PM
I posted on the M1917 forum that I usually try to remove the barrel without making a cut if I can do so. Even an old barrel can sometimes be useful. I once had to remove the barrel from a M1917 Eddystone, and knowing that those barrels are often very tight (they put them on with hydraulic machinery), I got set up with the usual barrel vise and a long handle on the receiver wrench. Then I really leaned into it. And almost fell on my face! That barrel was barely hand tight, but it had been on there for 60 years. So I never predict about barrel tightness.

Jim

Harry Bonar
March 5, 2007, 10:58 AM
Jim:
I got some Turk 38 rifles and had the same thing happen - one of them, I swear, I could have unscrewed by hand! Shocking, isn"t it:eek:
Harry B.

James K
March 5, 2007, 03:14 PM
Hi, Saands,

Sorry I forgot to answer your other question. As far as I know, Kuhnhausen has not put out a book on the M1903.

FWIW, I got an email asking how it was possible for them to make the extractor cut and install sights without screwing the barrel on and marking it. I assured the questioner that they did not do that. Is there any interest here in a fairly short piece on how they did that and what the draw lines mean?

Jim

saands
March 5, 2007, 03:16 PM
That's too bad ... his Mauser and 1911 shop guides have saved me a LOT of anguish over the years ;)

Thanks for all the info!

Saands

saands
March 8, 2007, 03:56 PM
Well ... I haven't shot it yet ... but the CMP 1903 "sewer pipe" barrels I was afraid of must have been out of stock, 'cuz what they sent has REALLY nice rifling and no pitting that I can see! :D :D :D :D

These 03a3's are REALLY nice ... I can't believe that I didn't already have one!

Thanks for all the info,

Saands

Clemson
March 15, 2007, 10:25 AM
Saands: Glad you got a good one. My experience with the CMP is that they describe very accurately what they have and stand behind it 100%. I bought an '03 and an '03A3 from them several years ago. They sent me a replacement extractor for the '03 when I found that it was not holding tension on the cartridge head. No charge. They also replace the rear sight on the same rifle when I discovered it bent. No charge. It's hard to beat that service.

Is there any interest here in a fairly short piece on how they did that and what the draw lines mean?

Jim, I would love to see a treatise on installing a Springfield barrel. I have done a bucket-full of Mauser sporters but no Springfields.

Clemson

saands
March 15, 2007, 01:18 PM
I finally did some barrel cleaning and what I saw almost blinded me ... I think that some of the rifles that were sent to the VFW posts must have been unissued after re-arsenaling ... the light from my flashlight in the breech hurt to look at from the muzzle :D :D

As for an explanation on the ability to cut and sight these (and I'm assuming the same would applyu to the Garand) pre-install goes, it would be a fascinating read. I've always assumed that some of the motivation for the coarseness of the barrel threads had something to do with tolerance margins on these operations, but I'm still awed by the ability to hold such tight tolerances.

Saands

James K
March 15, 2007, 10:15 PM
I think I will address the factory barrel installation in a separate thread. That way, there will be a lot of space for folks to tell me I am wrong.

Jim