A friend was showing me a gun the other day. It was a single shot cooey (model ?72?). He had the barrel and the stock cut down some and had it rechambered for .22 mag. There was nothing stamped on the barrel. I pointed out that someday someone would likely assume it was a regular .22 and shoot that ammo out of it. Would that be a problem?

Robin

Other than crudding up the chamber a little, no problem. The case of the mag is obviously longer ... so the 22 LR would colllect a little spent powder fouling at the ridge intended for the case mouth of the mag. Nothing a decent cleaning wouldn' t take care of.
This is my opinion, as I am not an authority on this issue. Hopefully some others will pipe in to set you straight.

Not only is a 22 WMR case longer than a 22 LR it is bigger in diameter. Yes, you could end up with a mess on your hands as well as hot brass and gasses in your face if and when the 22 LR case splits from being fired in a chamber that is too big for it. Whoever rechambered the gun should have stamped the barrel accordingly. My guess is the whole thing was probably a hack job.

You wouldn' t shoot a .223 out of a 22-250 would you? It will fit but it aint going to work. You won' t have the pressures that these cartriges will have but it' s the same scenario. The 22 mag case is longer, bigger in diameter, and the bullet is, I think, bigger also. Not a good idea.

BigBulls said it.........NOT A GOOD IDEA.

WOW!
I stand corrected.
I just mic-ed a round of each. Their case diameter' s at the case mouth are WAY different. My apologies.

Boom, maby, the rifle you are talking about uses only a staked bolt handle to hold the bolt shut, not real strong. Who ever rechambered it should be sentenced to firing 500 rounds out of it with out shooting glasses. I am a gunsmith and would never consider that job as safe. Hang it on the wall or do somthing with it other then shoot it!!!!!!!!!!!!!! You know, it is sad but there are people out there doing stuff like that and ruining guns all because either they are ignorant or don' t care. When in doubt check with some one who knows!!!!

Best bet wouldbe to take the rifle to a smith or machinist with a set of punch stamps and have ' .22 magnum' stamped on the barrel or else its accident waiting to happen.