I took the new 7 shot .357 GP100 to the steel range this morning with a wide variety of reloaded cases and had NO problems with cylinder rotation, lock-up and extraction.
I used only 105 rounds of moderate power target loads for the first part of the test because of how hard it is to replace what I shoot. The loads were all Acme no lube groove Hy-Tek coated 148gr button nose .358 wadcutters, firmly crimped in the crimping groove, with enough 2400 to give me an estimated 1000fps, using Winchester small pistol primers. There were 5 cylinders of my hoarded Starline cases and 10 cylinders of mixed cases. I shot about half at a steady pace single action, and the rest rapid double action. The gun got pretty hot to the touch!
I finished with only 5 cylinders of mixed cases using the Acme no lube groove Hy-Tek coated 158gr .358 SWC, with a heavy crimp in the crimping groove, and enough 2400 to give me an estimated 1350fps, using Winchester small pistol primers. I shot these at a steady pace double action. The gun got hotter!!
There were NO problems with any function of the pistol. I consider it a very reliable example of Ruger engineering. I'm going to be OK taking this gun anywhere a reasonable person would carry a medium caliber magnum pistol.