317 revolver purchased earlier this year. Performed flawlessly for the first 1000 (or so) rounds. Subsequently every few loads after a shot the cylinder refuses to advance, or does so with difficulty. On opening the cylinder, the shell from the just-fired cartridge is protruding very slightly (towards the rear), as compared with the other shells. Removing the shell (it's sticky) allows the cylinder to close easily and advance to the next unfired round.
FWIW, the 317 has been carefully cleaned, and the first occurrence of the problem generally happens after a few dozen rounds being fired.
Suggestions?