The Home Machinist!

I have a coworker that has a 22 ruger revolver with two regular 22 cal cylinders he asked me if i could stick one of his cylinders in the lathe for him and bore it out to 22mag for him but ive never done this before and figured id do a little research before i got him killed with a botched cylinder exploding in his face. any else ever try anything like this before?

I'd sure look into buying a mag cylinder from Ruger, first.
It is not going to be a fun job if done on the lathe. You can probably get a 22RF Magnum reamer from one of the reamer makers or Brownells for less than $50. That would be the best way to do the job. You would get the correct diameter for the case body, rim, leade and freebore.
If you do it by boring on the lathe, I'll bet that you never do another one.

Jay, Idaho

you can send those back to Ruger, and they will fit a mag cylinder and index it to the barrel. that way it won't blow up on you.

Ruger will also add part of the gun's serial number to the "new" cylinder so that people will know in the future that the cylinder in question is actually safe to shoot in that firearm. I recently purchased a single six in .22 and the guy gave me another cylinder that wasn't in the same rough shape as the gun. Upon inspection, it did have the right numbers etched into the cylinder, so I feel safe in shooting it.
David from jax

also when chambering a cylender, its done on a mill not a lathe,,