Took my definitely used M-28 to the range today and was pleased with the trigger and overall feel of the pistol. I was shooting factory 158 gr/1000fps lead SWC, not a hot load, recoil was easily managed. The first two cylinders shot just fine and extracted easily. The third cylinder was tight but they extracted. The fourth cylinder ... did not want to extract -- it would not move. Eventually, after a bit of gentle coaxing it did extract and I was able to remove the spent shells, but that was it for the M-28's debut range day with me. It's obviously not a new gun, but it's in relatively good shape. Any ideas what the problem could be? TIA.