There are differences of opinion. I say they will hold the pressures in the cylinder. The problem lies in the action. I would feel comfortable with many rounds up to standard loads. CCI Mini-Mags can be used safely for hunting purposes. 22 caliber shotshells are fine. The newer high velocity, increased pressures loadings are NOT for most any older 22 period. If you want to shoot the hot stuff, you do need a stronger firearm. Rugers, S&Ws and even Commanche I 22s come to mind. I know this isn't what you wanted to hear. There just isn't a easy answer. I shoot standard Wal-Mart brick 22s in mine regularly, I have shotshells and CCI Mini-Mags for times that I need them. I simply would not target shoot with Veloci-Raptor high pressure, high velocity ammunition. It is like asking a Totota Echo to race at the Indy 500. That is not what it was designed for.