I used to have one and regret selling it. I used mine to load .300 WM ammo for competition at 1000 yards, with sling and riflescope. Very accurate way to load match ammo.
the bolt is used appears to be very lightly i included close ups to show wear if any on lugs etc, and when you blast and have them reparked the roller does get parked as well as you can see in the last 4 i sold http://m14forum.com/px/111388-4x-usgi-bolts-3x-hrts-1xwinchester.html what some people do is just polish off the roller, the black roller is usually your indication that the roller was reparked