Jeff - although I guess there is no such thing as too accurate of a rifle, I generally don't advise my customers to do the bolt/action sleeving on guns that are to be carried afield - as I am presuming this Ultra Mag will be. Tolerances are too tight for reliability - dirt/dust issues. I do recommend you true up the action - lugs, threads, and receiver face - as well as the bolt face and bolt lugs - before installing the new barrel on a premium hunting rifle. This will usually result in a rifle that shoots 3" at 500 yards with good ammo - at a cost of about $450 to $500 complete. Going beyond that level of tweaking is really for only serious competition target guns, IMO - and then only in the hands of serious competition shooters. Regards. Roscoe