It likely used to be revolver specific, but it also works well if you want to get your da/sa gun below 5 lb on the first shot and some of the striker gun trigger kits can use the help also so I am told. Anyway Dillon 1050, federal spp, I have adjusted depth to the point where I deform the primer on some range brass and on other mixed headstamp brass just drive it deep, for the wheel gun it is all the same brass so the dimple is consistent.