Some time ago I picked up a M&P revolver, 4" blued square butt model, designated as the .38 S&W Special cartridge on the barrel. This seems to be a 1940s gun, possibly transitional, with non-V serial number 864XXX.
The barrel slugs correctly and the cylinder does seem to be properly sized for specials vs. .38/200 or .38 S&W. When loading the cylinder all standard factory loadings I've tried so far slide in properly, with no indication of a tight or too-loose chamber; nothing has to be forced and the cartridges don't start to slide out if tipped slightly. The cartridges will then sit correctly on the rim and accuracy with all tested rounds seems to be within the right groupings for a fixed sight service gun; no consistent fliers or similar. So far Magtech, Winchester white box, Remington wadcutters, and one cylinder of older Nyclads have been tried.
The trouble is that without variation, regardless of ammo brand, upon extraction the cases 'stick' in the cylinder, sometimes without moving even a 1/4", until what I consider excessive pressure is forced upon the extractor. After the first range day with it I assumed it might just be dirty from long storage and re-cleaned it, going much more thoroughly over the gun with solvent, penetrating oil in the extractor action, a heavy scrubbing with the brass brush and cylinder chambers with a brass .357 brush.
The next trip to the range yielded slightly better results with the wadcutters, in that the first cylinder would extract far enough without much pressure to withdraw the spent shells by hand, but then moving to the Nyclads the previous problem was encountered. A new cleaning involving the removal of the crane and cylinder itself has done nothing to alleviate the issue, and so I'm out of ideas. I can only assume that for some reason the brass is expanding, regardless of loading, and 'snugging' too tightly against the chamber walls to extract cleanly.
I have shot revolvers consistently all my life, and this is the first issue I've encountered with extraction issues like this that didn't either stem from fouling, a bent rod, or in one case a poorly bored chamber on a .22 I'm not a pro gunsmith by any means, but if there are any old hands and wiser minds around to lend a thought or just tell my a** to get it in to a professional feel free to let me know, it's all a learning experience.
She's just a shooter, not a museum piece, but I like the history of the old girl and so if anyone has any ideas to try, I'm grateful to you!