I have noticed a lot of surplus Weatherby Lightweight and Ultra Lightweight barrels avalable recently. Supposedly, Weatherby at some point changed their length or contour specs and surplused these out. I bought a stainless 25-06 Ultralightweight barrel, cut it off and chambered a 250 barrel on a Charles Daly Mini Mauser which was originally set up for 22-250. Just had to lengthen the box and bolt throw to max. It worked and shot great and is really light. I then saw that a lot of other calibers were available in Lightweight chrome moly without the dark finished flutes. I bought one in 338-06 on eBay for $100. (I got the 25 cal stainless for $82).

Here are some pics of the barrel.







As you can see, it is a cone breech design. The kicker is that all the non magnum calibers are threaded 7/8x18 and have a short 1" shank that starts tapering immediately, so that setting back and rethreading is not possible. The 250 worked because the mini had a thread diameter roughly .860", so it could be cut, turned slightly and rethreaded properly. The solution I am trying is sleeving the action threads. I took an old takeoff 8mm barrel, cut off the threaded section, chucked it in the lathe and drilled and tapped it 7/8 x 18 completely through for a tight fit on the barrel threads. I locked the lathe spindle and used the tailstock to tap the hole to keep it aligned. It is shown here with the barrel.





I then screwed the bushing backwards onto the barrel until really tight and chucked it back in the lathe. I turned it off until the cone breech was gone and the shank was the proper dimension to fit the Mauser action, bottoming only on the inner shoulder.





I then reversed the bushing, tightened it and took a very fine facing cut. It should be mentioned that the actual barrel contacts the inner shoulder along with the bushing, so there is no chance of varying headspace. I screwed it into the action and it is ready for cutting the final chamber.



Has anyone ever done this before? I know there have been a lot of discussions about large ring, small ring etc. This is definitely outside even the small ring category, but Weatherby has sold truckloads of these guns with 7/8" barrel shanks with no problem. Many are high intensity rounds and have caused no problems. The Mauser action is larger in diameter than the Weatherby the barrel came from. The actual chamber walls are thicker, since the threaded shank is now shorter than the original. I don't see any problems with this, but would like to hear any comments based on experience. It seems like a good way to use some quality fluted barrels which are very cheap.

The Browning BBR's receiver lugs are a separate threaded piece that threads onto the barrel, and then the receiver threads over that, making it a 3 ring circus. People have sleeved just about everything in the name of getting brand X barrel to mate with brand Y receiver. The major considerations when joining existing barrels to receivers is, sufficient material surrounding the cartridge, and a solid means to seat the barrel and set the headspace. Your solution, while not exactly mainstream, doesn't appear on it's face, to cross any lines. Don't forget the LocTite.

There is a lengthy discussion from a few years back on this topic on the gunsmithing forum; IIRC the final analysis was bushing the tenon is an acceptable practice.

Done right, as I think you're doing, it's great idea for the Weatherby barrels. If one was to you furnish you with a barrel, what would be the cost to bush/rework the barrel? Point being, add the labor cost to the barrel cost, and the barrel might not be all that cheap in the end.

I made the bushing from an old discarded mauser barrel. Total work time was about 45 minutes of my spare time (I'm retired). Total cost of the conversion was zero and took maybe 15 minutes longer than cleaning up and threading a barrel blank to a mauser. If I did it again, it may be faster. Bottom line was that I got a brand new fluted barrel (short chambered) for $100 in a chambering I have been wanting to try.

To have a smith do it wouldn't be as good a deal.

A local gunsmith made a switch barrel system on varberger rifles and a similar treaded bushing. He had a small/fine tread so it could be easy screwed on and off.