I’m about to source a new CM barrel for a Mauser Model B Sporting rifle, in the original profile, which is very slim indeed. I want to have the contouring done here (in New Zealand) so the new barrel can have original sights etc fitted and so it matches the inlet exactly.

I know there are some smithing kinks for slim barrels but are there any particular characteristics of the barrel blank that are useful to consider when the final result is to be very slim (e.g. rifling method, stress relief etc).

Cheers - Foster

The barrel has to be properly stress relieved. Any decent modern barrel will be. I have turned down barrels which were buttoned, cut, and hammered; all worked out fine. I have also turned down cut barrels which were not strees relieved. They warped with each cut. I once turned a Shilen (buttoned) to .460 at the muzzle and it worked quite well. A 30 caliber Omark (Sportco) was turned to .510 at the muzzle and shot exceptionally well. If you use a North American barrel, I have turned CM barrels from Shilen, Douglas, Krieger, McGowan, Montana Rifle, and all have been fine. Regards, Bill

Bill, be very careful with that statement. All of the "Experts" on this and other forums, many of them have never run a lathe, will tell you you're wrong. Hee Hee!

quote:

Originally posted by DocEd:
Bill, be very careful with that statement. All of the "Experts" on this and other forums, many of them have never run a lathe, will tell you you're wrong. Hee Hee!

Boy if that ain't the truth.

Never having contoured a barrel I'd be surprised if it didn't warp on me.
There's a lot going on when turning down a blank

kc, I've always left my tailstock clamp just the teensiest bit looser than usual, just barely loose enough to be able to slide very slightly as the barrel grows longer with the heat. May not be necessary but it makes ME feel better!
Regards, Joe

I've done the same thing on long parts turned between centers. You can change (foul up) the alignment by over tightening the lock on the tail stock or by as you say how much pressure is exerted by the center.

I just back it off now and then as the job progresses. I have though of getting a spring loaded center but have survived without it for quite a while so probably won't bother.
Chatter is the biggest problem and, occasionally, I have had to resort to using the steady for very light contours.
I've seen some clever vibration damping systems created by some old timers. Regards, Bill

Thank you gentlemen (particularly Mr Leeper), I can now proceed with confidence.

Cheers - Foster

Most interesting, I also have a Mod. B, Obie and find this discussion fascinating. What caliber-chambering are you using, may I ask?

I am curious as I now have two pristine Brno 21/22 actions and am considering what to build on these, when the other projects I have underway are completed. I would prefer a barrel length of 60cm. as it gives better velocities and I like the aeasthetics more, so, am curious as to what your project is.

I have two kurz rifles, both in 250 Savage. Both are a bit lame, one has no bolt, although I do now have a bolt body on the go for it, and the other is badly bubba'd, it needs a barrel, new bolt handle,stock and a saddle for front scope bases.

I want to keep them both as 250's

I have posted photos of the pair elsewhere on here and Nitro Express.

Cheers

I highly reccomend using a pneumatic follower. If you do a search in this forum you will find several old threads on it