All modern American 22 Hornet barrels take .224 bullets. There are some European rifles that still take a .223 Bullet. CZ comes to mind, I am sure there are others. Case life depends on your rifle chamber, action type and how hot your reloads are. In addition to that 22 Hornet cases are very thin when compared to other more modern high pressure cases. The case design does not lend it self well to long case life either. The long sloping shoulder lets the case grow considerably. I would imagine you will get any where from 2 to 5 loadings before the case becomes unusable. Depending on how hot you load for. Check the web area for head separation each time you reload. You may find you have to trim every time you reload too, those cases grow more than any other one I reload for; that is why they want to separate at the head, all that growth comes from right in front of the web. Some people have converted their 22 Hornets to a wild cat called 22 K-Hornet to get a sharper shoulder and less case growth. Not necessarily more velocity. Good Luck and good shooting.