I want my small ring M98 barrel to index in an additional 90 degrees (one quarter turn). Approximately how many thousands do I need to turn off the barrel torque surfaces to accomplish that?

Thanks

divide the number of threads per inch by one and then divide by 360 and then multiply the answer times 90. Will give you a one quarter (90deg) turn, Ideally. but go slow

Deleted - see repost - obvious typing/math error!

quote:

Originally posted by ssdave:
mauser 98 large ring is 12 tpi. 1 inch divided by 12 is .083" per thread. 1/4 of that is .021. Cut about .018 or if you're confident, .020, and recheck; tighten the barrel at least 3 or 4 times with well oiled threads. Then, recalculate using Jim's method, and do the final cut.

edited to correct my obvious math error on the first post!

Always undershoot on your math with Mausers. The threads are coarse, there are only approximately 4 of them in play and there is always a lot of crush on the face. Take your time, use chicken cuts and sneak up on it while crushing the action on a few times as you go. If you overshoot and have to make another turn you may not have enough thread left. 90% of the time when I overshoot a witness, it's on a Mauser. Bad luck, bad math, or maybe they just HATE me !

Speer, you stated that much more plainly than I did. I agree, I do a preliminary tightening several times on mausers, they creep tighter each time.

I'd like to add to the info already given . It's important to first determine which shoulder is actually contacting the receiver . I prefer to use the inner and use the ring only if the inner c collar is off .( and I'm too lazy to clean it up )

quote:

Originally posted by Jim Kobe:
divide the number of threads per inch by one and then divide by 360 and then multiply the answer times 90. Will give you a one quarter (90deg) turn, Ideally. but go slow

Or simply divide one by 48 (4x12) and get your answer (.0208). Allow .002 or.003" for crush. Be sure to ascertain on which surface the barrel is currently seating before you cut. Regards, Bill

quote:

Originally posted by Bill Leeper:

quote:

Originally posted by Jim Kobe:
divide the number of threads per inch by one and then divide by 360 and then multiply the answer times 90. Will give you a one quarter (90deg) turn, Ideally. but go slow

Or simply divide one by 48 (4x12) and get your answer (.0208). Allow .002 or.003" for crush. Be sure to ascertain on which surface the barrel is currently seating before you cut. Regards, Bill

That would be too easy

Thank you all for your advice.