Sorry about mixed terms.
I pulled bullets from three factory rounds and then full length sized the cases and measured, 2 were 893", 1 was 894" this is a bit more than most of my old fired brass.
Jellybean; I know how a 1911 is supposed to work. The step in the barrel left by the chamber reamer is the "shoulder" I was referring to above, I had a mind spasm and couldn't think of the right word. In this discussion I should say case mouth and barrel step, but didn't always do so.
If you look at what Kuhnhausen has to say and his illustrations about barrel fitting , ramping, and chambers, he is clearly talking about what happens when the round is not pushed forward until the case mouth hits the step. See above for what mma10mm, rock185, and cjw3 say about what is happening inside.
Kuhnhausen says headspace should be checked with a headspace "go" gauge in place, headspace then is the "go" gauge (.898") plus what ever additional feeler gauge the barrel will close over. The Max is .920" which is the no-go gauge size. This check is best done with the extractor out. Since the barrel should be locking on the first locking lug, a measurement from the barrel extension to the step will only approximate the headspace.
While most match barrel headspaces are .898" + .010" or slightly less, Mil Spec Pistols are up to the .022" allowed.
Dead center of the headspace tolerance is .909". Since we know the brass is likely to be around .890" We would have .019" of space either at the case mouth or between the case head and the slide or split between them.
Worse case is a max spec headspace and short brass, then we have .030" of slop.
The crux of the argument is whether the round is pushed into the chamber by the slide, if so the case mouth probably will not be at the barrel step. If it does get to the step there is nothing to keep it there.
I pulled bullets from three factory rounds and then full length sized the cases and measured, 2 were 893", 1 was 894" this is a bit more than most of my old fired brass.
Jellybean; I know how a 1911 is supposed to work. The step in the barrel left by the chamber reamer is the "shoulder" I was referring to above, I had a mind spasm and couldn't think of the right word. In this discussion I should say case mouth and barrel step, but didn't always do so.
If you look at what Kuhnhausen has to say and his illustrations about barrel fitting , ramping, and chambers, he is clearly talking about what happens when the round is not pushed forward until the case mouth hits the step. See above for what mma10mm, rock185, and cjw3 say about what is happening inside.
Kuhnhausen says headspace should be checked with a headspace "go" gauge in place, headspace then is the "go" gauge (.898") plus what ever additional feeler gauge the barrel will close over. The Max is .920" which is the no-go gauge size. This check is best done with the extractor out. Since the barrel should be locking on the first locking lug, a measurement from the barrel extension to the step will only approximate the headspace.
While most match barrel headspaces are .898" + .010" or slightly less, Mil Spec Pistols are up to the .022" allowed.
Dead center of the headspace tolerance is .909". Since we know the brass is likely to be around .890" We would have .019" of space either at the case mouth or between the case head and the slide or split between them.
Worse case is a max spec headspace and short brass, then we have .030" of slop.
The crux of the argument is whether the round is pushed into the chamber by the slide, if so the case mouth probably will not be at the barrel step. If it does get to the step there is nothing to keep it there.
