You'll need to re-barrel also, not just re-chamber. You can't shoot 338 cal bullets thru a 308 cal barrel. You'll have to check with a local gunsmith on the actual cost but the barrel should cost far more than the labor to install it.
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If you can't shoot enough gun then go home!
Thanks. I knew about the new barrel. I didn't specify because I thought that was a no-brainer. I guess I could try to fire-form the 308 barrel to 340. (that was a joke, of course. don't you kiddies at home try that).
Sounds a little pricy for something I don't really need. I think I'll skip it.