[stash247]

Everything Bindernut offers is true, but there are a couple of omissions of information, here.
A .22 long loads a 30 gr bullet, in a LR case, but the bullet likes a 20" rifling twist; the .22 LR, with a 40 gr bullet, a 16-16 1/2" twist, best.
There is no way you can tear up that rifle, with any ammo, as it is hell for stout, but the .22LR ammo may lead the throat of the barrel, but you can't hurt the rifle.
If you have the means, check the rifling twist rate; should it be 16", or close, a gentle touch with a good accuracy reamer, in the chamber, to extend the throat, and leade, could really make it a fun rifle, but if the riflng is slower than 18", I'd keep it clean, and leave it alone.