I've made a decision to stop using a FH that has to be timed. I don't use a can and have always just put an A2 bird cage on my rifles. I got a Smith Enterprise Vortex. They recommend to not use any kind of washer or shim. I read a post somewhere, a guy said he uses a crush washer with them, just his personal preference. Anyone use these FH? How do you recommend installation? Should I use rocksett? Good or bad experiences with these FH?