In the "Cleaning GP100" thread, I posted the following:
I'm still trying to figure this out. I'm not able to get it to do it with any repeatability and I'm wondering there's an actual issue or not. When it happened, the cylinder was difficult to close.It's weird, sometimes while I'm cleaning it, the cylinder will get sticky getting it back in and the trigger pull gets really heavy. But then I'll swing the cylinder out again, give a wipedown on all the places that typically need it, and it's back to normal. I'm not sure what causes that and whether it's indicative of something off with the gun itself, or maybe getting junk I can't really see in such a spot that causes it.
I've had it happen twice with my 4" GP100, not with the new 5".
[Edit, seems maybe it's able to happen if I close the cylinder a certain way but I'm not sure why or how. First trigger pull was slightly heavier and then it went back to normal for all 6 chambers]