Determining barrel looseness

[Dean Romig]

Removing metal when fitting a set of barrels should only be done with the use of the finest two diamond files you can find. The coarser of the two (which should be about 400 grit) is for removing metal. The finer grit is for polishing to a final fit. Smoke the lug area first, then close it as far as it will easily go without forcing it. The smoke will have rubbed off where it is too tight... this is where you use the file a bit and then re-smoke it. It is a long process but will give the precision fit you need.