USGI bolts come up from time to time in the EE.
Swapping the bolt is pretty straight forward, fitting it properly.... Not so much. But defiantly do-able with a decent understanding of how parts fit and work together.
The big question is, will it actually improve headspace in your rifle.....
Lately, what with the scarcity of USGI bolts, I generally only recommend swapping if a new short chambered barrel is also installed. USGI bolts generally cost $350+ lately....
My $.02