Gbnk82,
Check out this link. This has some great information regarding modern ammo for the M1. You can shoot commercial ammo but you need to be careful what your shooting. Will your Garand blow up using some hot ammo? Maybe, maybe not. For sure, it will NOT be good for it or the op rod (and those get expensive to replace). Before I knew anything about Garands and what to feed them I put any 30.06 round I could find in it. It took it all and came back for more. Now I know better and wouldn't do that.
I'll eventually get one of these gas screws but until then it's HXP and some of the commercial that the site shows as "safe". Right now I reload for mine which I think is a lot of fun.
http://www.garandgear.com/index.php?...arand&catid=39