you can choose what manufacture you want and a general condition but muzzle wear, throat wear, year of manufacture and mismatched parts are luck of the draw. I asked for service grade, that is a gun that actually met service requirements, there are several different grades, prices depend on grade.
most of the ones you see on here are service special grades: service grade parts with brand new stocks. they look pretty and normally have low wear but lose a lot of history in the process.
I was lucky, a DD214 can be used as proof of marksmanship skills so I didn't need to do any of that jazz... it's also a little sad because in the navy very few people even passed the pistol qualifications, no less took the extra initiative to qualify with rifles... I paid to qualify in both though... I think the navy rifle qual would be fun with an M1 instead of M16
another question for the masses, are CMP garands good to go out of the box or do they need a thorough strip and cleaning before shooting?