That's cool, I didn't even know those existed. But I think this is probably for the best. Less money invested in a barrel I'm just going to replace eventually anyways.
1/2"x28 is the AR-15 threading, which is pretty small for a 308. You can go 9/16"x??, whatever that common threading is for rifles. There are many brakes threaded for that 9/16" threading also. I have done several of those. The 9/16 is common on your sporter size barrels.