Quote:
Originally Posted by Andyd
Jerry Kuhnhausen explains the barrel tightening procedure not with a specific torque but that the barrel should be easily threaded in until 6 minutes before the front sight is in the 12 o'clock position. S&W used to pay the assembly crew by the number of guns assembled and overtorqued and canted barrels were the result.
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I have found that it kind of depends. If your putting on a used barrel it is different than a new one or one with freshly cut threads. What I do now is run the threads in by hand till it tightens up and then back them out a turn or 2 a couple times. You will gain a bit each time as the treads work themselves together. Lathe cut threads and even those that have had a die ran on them have little imperfections that "iron out" as you run them in and out. I don't believe I can tell what had tight with 6 minutes left is until the treads have been run a few times. Same goes for the shoulders. Take a look at those with magnification. Tiny imperfections. It is a feel as much as anything else. That last little bit between canted and just right. lol. Gets too hard, back it all the way out and try again. Threads wear together a tiny bit every time. Run a piece of 400 grit emery on a flat hard backer a couple times across the face of the frame and maybe a fine jewelers file around the barrel shoulder, Just to clean up the machine cuts a little bit and you will get a few decrees. Just slamming them together one time every time isn't going to work out.
The python barrel I put on put on the model 10 frame. It was a 32 pin barrel which meant it had .563-32 threads. I needed .540-36. After I took the extension to .540 and got the correct threads on it and even ran a .540 die over it was still kind of sticky and I had to run it in and out of the frame a few times to get them to run smooth to each other and every time I did it and hand tighten the barrel to the frame I got a few more degrees. Butt then it was about at 20 degrees past. Instead of removing material off the barrel shoulder I milled it off the frame face. Now the frame face is dead square, and smooth, same with barrel shoulder and the barrel goes in smoothy and gets hand tight hard right about where I want it before I stick on the frame wrench. But, I am not going to finish torquing on the barrel yet. First I want to mill the frame for adjustable sights and a piece to match the barrels rib. If I torqued on the barrel and then removed it, the next time I did, it would not take the same amount of torque to get it perfect.
But, if S&W spent the time I spend to fit a barrel they would have to charge a zillion bucks for each gun. LOL. But, there is really no excuse for what is going on. with canted barrels. There is some leeway in torque and it I was sitting at a bench fitting barrels I would screw one in and see where it ended up. Then either finish it with sights at 12 o'clock or run it out and then take a barrel from either the loose pile or the tight pile and try again. This would clue me in to what was up with the original frame and barrel. I bet most of the time the second barrel would torque up at 12:00 within torque tolerances. It should even out some frames taking a very slightly long and some a slightly short. I wonder how many barrels an hour they are supposed to do?