This is the best thing to hit the bolt rifle accurizing market for actions! This is not a sacrificial collar that only does round style receivers. It?s a jig that works on round, square, flat bottom-round top, long, and short. To date all Remington bolt actions, long and short. Winchester's long and short. Sako's and I mean all of them. Savage's long and short. Brno, Marlin, Weatherby, Ruger M77, etc.. The one that has not worked yet is a Ruger MK II 77 with the investment cast trigger hanger.
The action jig is held by a 4 jaw chuck . The rifle action to be accurized is held inside the jig. With 4 front and 4 rear centering adjustment pads, the rear having two locations for long & short actions, the center-line axis of the bolt bore raceway can be perfectly aligned with the rotating axis of the lathe. All single point machining of the receiver face, lugs, and threads will be concentric.
Perfection is obtained by the use of two dial indicators to set perfect alignment. One placed on the alignment manderal at the reciever face and the second placed at the end of the manderal . When both dials indicate 1/10,000 or less runout at the same time and in the same rhythm, perfection has been accomplished not desired. Once dialed in you DO NOT CHANGE OR MOVE the setup. All machining will be in perfect relation to each other and all to the axial center of the bolt bore raceway!
With the once accepted method of turning a collar with the action between centers and then mounting in a 4 jaw and indicating only the collar in, two devastating accuracy robbing mistakes have been made. #1 you have moved your setup form your collar cut and will be machining from a secondary setup. You have lost center line alignment. #2 you dialed in the collar around the action in a four jaw chuck to 1/10,000 or less and believe you have achieved alignment. Here is the fly in the soup. Are the jaws on your chuck perfectly parallel with the rotating axis of the lathe to 1/10,000. If you put back or leave the mandrel in the action and check the runout at the end of the mandrel, you will with a sinking feeling see the action rotating in a progressively larger cone as you move away from the collar you dialed in on. The problem with the collar system is no way to take out this misalignment in this type setup. ALL MACHINING WILL BE INACCURATE & ASKEW FROM CENTER LINE OF THE BOLT BORE!