Not in a RZ or patriot.. but I use one in my custom 10mm, a colt .45 Govt. and a 9mm Govt. and I switch them into my Pointman too occasionally.. I love them, I think they are great, expensive, but they really do make a difference to me and my friend who put me on to them... We were shooting Pins and he had one in his 9mm Govt. Shooting Federal 147gr. and a guy who had never shot before picked up the colt and cleared a 6sec. table. That was enough for me to try it and I've never looked back..