The 10-22 will NOT hold the bolt open on the last shot regardless of what anyone says EVER. There was an aftermarket mod that allowed this, but it was only with use of a special magazine. I'll take a modified 10-22 with money thrown into it all day over a 15-22, but that is what it is. If you are going to shoot a competition that requires fast reloads, the 15-22 will be faster hands down. On top of requiring the bolt to be racked on reloads, the 10-22 also can be fiddly with magazines. Also, 10-22's can be finicky and a pain to diagnose failures. Once thats figured out, they will run like clockwork, but it can be a process. Lots of people are big on the 15-22 and I don't think I've ever seen one fail in competition aside from light strikes. Have not witnessed one stovepipe in the few competitions I've been to. The one my cousin got last June however was a solid piece of junk though. Becomes a bolt action very quickly for whatever reason. Too bad there isn't more aftermarket support for this gun.