I have a Atchison .22lr conversion (sp) who ceiner bought his conversion from. it has been used in several different AR-15's and one M-16 after a little polishing and breaking in it functioned flawlessly for several hundreds of rounds with 30 round one trigger pulls.
in my HBAR accuracy was exceptional. I tried the aguila ss 60 grain bulleted 22LR for a kick and the short case hung up in a stove pipe but a little oil fixed it up.