DO NOT dry fire New Departure (Safety Hammerless) Top Breaks. The 32' Safety's in particular are notorious for breaking firing pins.
Any S&W with a hammer mounted FP - Snap, snap, snap (clear it FIRST)
I still don't recommend much of it for top breaks. Parts will be tough to get.
I am very reluctant to DF rimfires, but I have not seen a ding on a kit gun or K-22 WHEN THE GUN IS TIMED PROPERLY. The pins don't reach the bottom of the rim recesses, but I still can't enjoy it and use snap caps.