If you look in your manual it tells you not to use hyper velocity ammo such as CCI Mini Mag in the 10-22. The cases are longer in some of these and I "THINK" that`s the reason, at any rate they say to stay away from it and that may be your problem...............
You might be thinking of a different rifle or maybe a manual that came with a target barrel.
Copied from the manual available on the Ruger website:
The RUGER® 10/22® CARBINE and 10/22 RIFLE are chambered for,
and designed to properly function with, only the 22 caliber Long Rifle rimfire
cartridge, standard, high velocity, or hyper-velocity, manufactured to U.S. industry standards.
I have put many CCI Mini-Mags, Stingers (which actually are a little longer), and other hyper-velocity ammo through my standard 10/22 barrel with excellent results. I have not tried any of them through my target barrel.
Ammo that I have had problems with include the Federal American Eagle hollow-points (non-bulk pack) and Remington Golden Bullet bulk pack. The Federal AE was the absolute worst .22 ammo I've ever used - very inconsistent loads and some that wouldn't fire at all.
For good cheap plinking ammo I'd go with CCI Blazer and Federal Classic. I've shot many thousands of rounds of both with few problems. Old Winchester X stuff was really good, too, but I haven't bought any in years.
I've run my 10/22 super dirty and it doesn't seem to be a problem until the firing pin channel gets mucked up enough start deflecting the firing pin (causing failure to fire). Every once in a while you just have to take it apart and give it a good cleaning. It seems Ruger could have easily solved this problem by running a pin or something above the firing pin, but for some reason (maybe a good one that I haven't thought of yet) they didn't.