spec4 e4 Posted June 24, 2007 Report Share Posted June 24, 2007 Ok this maybe an dumb question but is the A&B barrel threads different then the Mauser LR threads? I have an A&B barrel that will not screw into the receiver. Thanks Spec.4 P.S. This company is running us to death, but will love the money . Link to comment Share on other sites More sharing options...
z1r Posted June 24, 2007 Report Share Posted June 24, 2007 Not a dumb question at all. yes, the threads are different. The mauser uses 1.10" x 12 tpi whitworth threads (55 degree) while the A&B barrel is 1.10" x 12 tpi std threads (60 degree). Brownells sells a tap made to clean up teh receiver threada but I find it easier to just cut the proper threads on the barrel. Why the US manufacturers continue this practice is beyond me. Link to comment Share on other sites More sharing options...
sonic1 Posted June 24, 2007 Report Share Posted June 24, 2007 will it not make up all the way .or just not start in the action at all ? Link to comment Share on other sites More sharing options...
machinist1 Posted June 24, 2007 Report Share Posted June 24, 2007 Hi, If your barrel will only screw on part of the way, try some lapping compound on the threads. If you don't have lapping compound valve gringing compound will do the same thing. Preiodically wash out the compound and check the fit as you can make it too loose of a fit. Link to comment Share on other sites More sharing options...
tinkerfive Posted June 25, 2007 Report Share Posted June 25, 2007 Basically what Machinist 1 said. I used an A&B barrel a while back that was extremely tight and had to use valve grinding compound to get it to go on. I think that they (A& hold to the upper side of the tolerances. Hey you can always take some away, it's harder to put some on. The problem you are having and I had was that the barrel was on the "+" side of the tolerances and the receiver is on the "-" side. Tinker Link to comment Share on other sites More sharing options...
spec4 e4 Posted June 25, 2007 Author Report Share Posted June 25, 2007 the threads start then stop. I just order or see if I can borrow the tap. Thanks all. I thought I was going nuts. 1st A@B barrel. spec.4 Link to comment Share on other sites More sharing options...
spec4 e4 Posted June 25, 2007 Author Report Share Posted June 25, 2007 I got an new in wrap F54 barrel in 260 Rem. for $25.00 from an friend saying it was the wrong size his lost my gain. spec.4 Link to comment Share on other sites More sharing options...
z1r Posted June 25, 2007 Report Share Posted June 25, 2007 Hard to beat that deal. I've been wanting to try the .260, let us know how it works for you. The problem you are having and I had was that the barrel was on the "+" side of the tolerances and the receiver is on the "-" side. That's an interesting statement when you are trying to fit together two different thread forms. The real issue is you are trying to put a square peg in a round hole. The allowable tolerances for a std thread would not be the same for a whitworth form thread. Most likely the way to solve this in this case is to lap like everyone has suggested. But this is the big reason that I do not use pre-threaded barrels unless the have the proper 55 degree thread form like Lothar Walther supplies. Link to comment Share on other sites More sharing options...
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