No the .22 mag has a larger diameter bullet so even if you cut the chamber longer it would cause an increase in pressure and the bolt is only going to be calculated to withstand the normal pressures of a .22 not an overpressure of a .22mag being swaged down a smaller diameter barrel.

You can fire a .22 out of a .22mag barrel though. and it will still be accurate enough because the hot gasses cause the base of the round to flow slightly and it will still grip the rifling.

minktrapper wrote: »

As the title says. Can the humble 22 lr be fired in a magnum chamber and barrel.

The answer to your question is yes it can, but don't do it because
1 it is not safe, the bullet velocity is vastly reduced, if firing out of a rilfe barrel the bullet may stick in the barrel.
2 it wont be accurate, with loss of velocity and magnum chamber sizing the bullet will move a lot in the chamber and barrel once fired.
3 I personally don't like the idea of having a magnum chamber in my firearm and shooting a shorter round, 22lr wont reach the rifling when seated so its going to be fired in the smooth chamber and then hit the rifling in the barrel, in accurate smallbore firearm's the bullet is pushing right up into the lands and groves of the rifling.

You CAN do it ,if you have a chamber adapter for 22 lr to .22 magnum.It takes up the slack in the chamber and allows you to fire the smaller caliber safely.However they can be hard to get insuch a small caliber, so alot of people have used spent 22 mag shells with the end cut off and the .22 lr inserted in that.Some .22 mag brands work extremely well for this,others not so.

LATER
This is the company that makes/made them in Alaska.Dunno if he is still in busisness.However I would say two other things about this. [1] Wear shooting glasses when using,as there will be possibly some hot gas flashback which is painful,and [2] Dont expect sub MOA groups out of these either. Paper plate at 30 meters type accruacy is more like.

https://web.archive.org/web/20180210083341/http://www.mcace.com/adapters.htm

tudderone wrote: »

I did do that (firing lr through a magnum) years ago when young and stupid, the case bulged out and distorted and the accuracy was not that good.

It just doesn't work right the tolerances are all wrong, but look on the bright side your older and smarter now