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12 Whitworth V-threads per inch( rounded crest and root), 55 degree thread. Greater thread diameter is 1.10 inches. If yours is a 24/52-C model the shank is .625 inches long. If a M48 or 24, 24/47 it is .670. The extra .045 is a .700 diameter extension for the safety breech feature.
 

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12 Whitworth V-threads per inch( rounded crest and root), 55 degree thread. Greater thread diameter is 1.10 inches. If yours is a 24/52-C model the shank is .625 inches long. If a M48 or 24, 24/47 it is .670. The extra .045 is a .700 diameter extension for the safety breech feature.

Just curious, I know the greater thread dia. on a Small Ring is, I believe, .2" smaller. Are threads, however, I understand are the same as a Large Ring. (12 Whitworth V-threads per inch( rounded crest and root), 55 degree thread)./

I ask because I'm toying with the idea of fitting a Norwegian .308 Large Ring Mauser barrel on a Turkish Mauser action...

Thoughts?
 

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Perfect..thanks! Should make for a VERY interesting rifle...since I already have a Turk action and a Norwegian target barrel (two different projects that never worked out), now I can just build the rifle around then...can you say MOA?...:D
 

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...I have never cut this type of thread before...

Neither have I, which is why I'm taking the barrel to a machinist for that part. That way i get to watch, get in his way and be a general PIA so I can learn how to do it myself...good thing he is a friend of mine!!! :D
 

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Your threading cutter is cut to a 55 degree angle instead of the 60 degrees of the usual inch threads. After that, it's relatively simple. The lathe is a great tool that makes much of the difficult simple. Keeping one running in a third-floor apartment, though, is a bit of a challenge....

If your machinist friends are set up to cut metric thread pitches, you might have them cut the shank in the original M.28x2 thread.

The M.48 shank is longer than standard by .045 or so, to allow cutting the breeching ring for the bolt. BobVz caught that one earlier in the thread, though.
 

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For those that like to do things totally themselves ...... Brownells sells (at least they used to) a pre-ground 55 degree tool bit for lathe threading said Mauser barrels. As for cutting the threads, you set up and cut them the same way you cut any other thread on the lathe, except your barrel blank shouldn't be your first thread cutting project! If you have a good grinder and gauge, you can grind your own tool bit. Perfect thread form (rounded crests, Vee's or whatever) and 100% mating depth of the threads is not necessary. There is plenty of holding strength with even a 50% thread mating depth. The barrel will not come out of the receiver (unless you blow it up!)

Brownells (and I think Midway, too) sell a thread die for the Mauser thread. This is intended to be used for cleaning up damaged threads and not necessarily for threading a barrel from scratch. Incidentally, a whole lot of Mauser barrels have been threaded and installed by cutting a common 60 degree V-thread - to my knowledge, none of them have blown out of the receivers. However, since one can readily obtain the 55 degree tool bit (or grind one) why not do it right? Anyhow, have fun and good luck with your project.
 

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Discussion Starter · #10 ·
Thank you for all of the information. I finally had a chance to try cutting the threads last night. I got at HSS tool bit cut on a Wire EDM machine at work to the proper 55 degree angle with a 2.5 degree relief angle wired on it. I ended up leaving the table engauaged for thread cutting the whole time and I just backed the tool out and stopped the machine. Then I would run it in reverse untill I got back to the beginning again. It took a little while but the thread turned out great. I ordered the barrel last night from midway USA. Im going to try to get it installed on the reciever this weekend.
 
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