If a .22 has a dozen bullets in the barrel, it may be not be in first class, or even entirely safe, condition, even with bullets removed.
Yeah, but that is to be determined after they are out, and the barrel cleaned thoroughly. I would suggest that an avaerage rimfire barrel would likely withstand the pressure bau a higher power cartridge, likely not, but that's just theory, and reality has a way of confounding those!
The usual chain of events is a single dud round gets a bullet lodged in the barrel, then a few more get stopped, building a blockage that usually defies hammering as a means of loosening.
My first experience, was with a gun that had been crammed full of assorted crap in order to convert it to a toy for a kid. Fully stuffed barrel. Mostly lead bullets, but some other stuff, know not what, it all came out with the bronze drill, and eventually the bore came clean.
Lots of pretty good pictures of guys running more than a full cylinder through a revolver, on line. I clearly recall one that the fellow had, that he said had only stopped when the action ceased to work. Barrels like that make pretty good cross section show and tell pieces, if they are actually damaged, but again, I would be looking to getting the bore cleared out THEN assessing the damage, if any.
Some pictures for the audience's perusal, including a few showing why trying to shoot the obstruction loose is a bad idea.
https://www.google.ca/search?hl=en&...j0i5i30k1j0i8i30k1j0i24k1.su2UppoTvpc#imgrc=_
Cheers
Trev