I re-machine a lot of Remington actions (also a lot of Winchesters, MRC's, and various military actions) because people want it done. On my own rifles, I re-machine when it seems necessary. Back in the day, Mike Walker recommended re-cutting the face of a 700 and that was about it. When one pulls the original barrel off, it is often apparent that the recoil lug has not contacted the receiver all the way around. Plainly, that is a receiver which will be improved by re-cutting the face. Whether or not this will have any effect on performance is another matter.
If you are unhappy with the chamber, perhaps you might consider simply having the barrel set back a couple of turns and re-chambered (probably not by the original 'smith unless he can improve his methodology).
The improved resale value of the custom action may well be factual but it isn't probably as great as one would hope. The thing is, you have this action in your hand.
If Benchmark wants 850 dollars to re-barrel and the barrel is worth 350, they are figuring on 500 dollars in labor for the job. That is a substantial charge for barrel fitting IMO but it's their shop. GD

Last edited by greydog; 04/16/14.