Mauser 98 rebarrel (new question added)

[jackieschmidt]

Turning the stub in the three jaw chuck, or any other chuck, results in a piece with the threads perfectly perpendicular to the face as long as the piece is not removed. A ll machining is done with one set-up. If the piece is to be re-used, it has to be set up in the four jaw and dialed on the circumference and the face. I generally just make another piece. Seating against the inner seat should result in the receiver face being parallel to the seat. This, providing the threads are perpendicular to the inner seat or the threads are loose enough to allow the inner seat to be the locator. WH

Will, I did leave out the part about making the threads on the loose side. Thanks for including it.

 

[SBS]

I understand that Mauser designed the 98 action to torque on the inside shoulder to keep the barrel diameter smaller. Most if not all of the military barrels I have pulled are not tight against the outside shoulder -- in fact, a goodly number have a small gap between the barrel shoulder and the receiver. Since modern rifles only bear against the receiver face, I reasoned that will work on the 98 also, given a decent sized barrel shoulder. On a similar note, you quite often seen restocked Mausers that have the stock cracked behind the tang and sometimes even behind the recoil lug and/or magazine housing. The design of the short (in depth) recoil lug worked fine when against the steel crossbolt of the military rifle. Not so well when dropped in a wood stock without being bedded and recoil moves the metal back as the wood compresses in the small surface area of the recoil lug. The '03 Springfield suffers the same problem if unsupported by a steel crossbolt and left unbedded. A lot of times when we take military actions and sporterize them, we have to remember why they were made that way and find a way to make them work best for our sporters. Not being argumentative about the rebarreling question, just explaining my reasoning.

 

[Dave in WI]

Thanks for all of the great replies!
Now, let's muddy the water a little:
Do you cut the threads at 60° or 55°?

 

[Will Henry]

I cut at 55, but I don't think it makes a lot of difference. WH

 

[SBS]

55 is correct. Short and coarse threaded as the 98 tenon is, best to get the threads fitting properly with most engagement you can get and still screw on by hand.

 

[Sniperhandle]

Thanks for all of the great replies!
Now, let's muddy the water a little:
Do you cut the threads at 60° or 55°?

Here is the tool I use on Mausers, Works well and is the proper 55 degree Whitworth thread. Just don't forget, If you are using the compound, Set it to around 28 degrees, Not 29.5 or you will get a wonky thread.

If it's an Asian machine that gets set at 60 degrees, I would assume you would set it at 55 degrees, But I am not sure, Someone that uses 55 degree inserts on an Asian lathe will jump in and let you know.

If you are using a BXA tool holder, It takes the 250-201XL tool holder.

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[Will Henry]

I grind a HSS tool for the 55 degree thread. I set the compound at on the heavy side of 27. I prefer contact to occur at the top of the thread first, if it has to contact anywhere first. The thread will deform enough, under load, to provide full contact, and the deformation will be on the barrel thread; not the receiver. This is the potential issue with the use of a 60 degree thread on the barrel. Contact will be at the root of the barrel thread and the top of the receiver thread. Deformation is likely to occur on the receiver thread.
Having said all this, I know some well regarded gunmakers who cut 60 degree threads for Mausers and have suffered no ill consequences from the practice. WH