There is kind of a spectrum that these sort of problems occur on, with the remedy at one end of the spectrum being cleaning the cylinder and the remedy on the other end being replacing an improperly machined cylinder. Occurring most often (in my experience) is a remedy in the middle of the spectrum which involves tightening one of those fluffy bore cleaning attachments into a drill, coating it lightly with Mother's Mag Polish or some other mildly abrasive compound, then polishing the (cleaned) cylinder chambers with the drill and attachment.
Best to use a slower drill speed at first to keep the polishing compound from flying everywhere. As the compound disappears, you can use a higher drill speed to get a smoother surface. Best to remove the cylinder, but not absolutely necessary if you don't feel confident doing so. Just make sure you maintain good control of the drill so the chuck doesn't damage the finish of the gun.
If the spent cartridges simply won't come out with anything less than the most extreme force, I suspect you're at the bad end of the spectrum, with machining or cylinder replacement necessary. I had this happen once on a Heritage 1873 Colt clone in .357 mag. But I sent it back to Heritage and they made it so the spent cartridges came out like they were greased with butter. Didn't even need to use the extractor. Very fixable problem.
