[RickB]

The barrel lower lugs, forward of the link pin, should not contact the slide stop pin, either coming or going. If the vertical surface in the frame is too far forward, the barrel will hit it prematurely. If it prevents the barrel from fully seating on the frame, the slide could rub the barrel as it cycles; if there was actual interference between the slide and barrel, it could damage the upper lugs. When the barrel is completely linked-down, is it free of the slide at the top? I think Schuemann likes .015" of static clearance. If you're using a standard-length link, the slide is not rubbing on the barrel as it cycles, and there is evidence that the barrel is stopping on the vertical surface in the frame, then the timing/fit seem to be OK. Are you having problems that lead you to believe something isn't right?

 

[RickB]

Kuhnhausen's first book says the barrel should stop on the top of the frames - not so much that it "should", but that it will. In the second volume, he reprints Schuemann's barrel timing/fit info, and says the barrel should stop on the vertical surface. I suspect it was not possible to build G.I. pistols with sufficiently close tolerances to guarantee the barrel would stop in the ideal manner. FWIW, my Delta Elite and Detonics Combat Master both stop on the vertical surface, as they came from the factory. I have "fitted" (then why is it called pre-fit?) a Schuemann barrel in that manner to my M1911A1, and it is still going strong. I think Dane Burns posted here, that he fits his barrels for more of a corner contact fit, with the junction of the tube/lugs contacting the shoulder of the frame, rather than full contact between the rear of the lugs and the vertical face of the frame.