Do new guns require a significant amount of breaking in time?

i have 2 marlin model 60 semi-auto 22 caliber rifles. one is brand new and the other 17 years old with alot of rounds fired through it. while out shooting the other day 2 different brand names of ammo was used. while the new rifle had some jams and failures to feed with one brand of ammo, the older rifle functioned flawlessly with both brands of ammo. it appeared as though the problem with the jamming in the new rifle was a couple of stovepipe jams, but most of the time the bolt failed to come back far enough to push another round into the chamber. i tend to think the reason is a combination of 2 things in the new rifle. one brand of ammo wasnt quite as powerful as the other, and maybe because the the new rifle being new and with a stiffer recoil spring, it was faling to come back far enough to engage a new round. also the new rifle has a much stiffer trigger pull. are these monir problems likely to correct themselves as i fire more rounds through the rifle?