With the CrownRidge barrel works Hex Nut, I will be using a "well fitted", Crescent wrench ( LOL ! ) or, a Crows Foot, Box end type of wrench, very carefully ! I'm using, a regular, Large Vise with, Plywood & Leather, "padded Jaws" and putting the Action in it, sideways ( Ejection Port, UP ) and clamping on, the Jig at the bottom of action and the Picatinny Base on top, to hold the action securely, while tightening, the barrel Nut.
Several Vid's on YouTube, will show you, how to fit, a Pre- Fit barrel.
ONLY watch, real Gunsmiths and NOT, the PHONY'S, that know,.. nothing !
You will, probably need to talk to Jim, at NSS about, the Re- Cut threads / Trued actions and about, the Barrel "Match up", capabilities for any future, Barrel use.
MOST people, I've heard say, NOT to do IT as there is not much, interchangeability with, OTHER Barrels, after re-cutting, your actions, thread's ! But it's, your choice.
To truly make, a SUPER Accurate, "Target Rifle", go with, a Top Notch Gunsmith and a shouldered Barrel like, a Bartlein, Krieger, Brux, Muller, etc., using a "fitted and Gunsmith chambered" Barrel. And while you at it, you might as well, put IT on, a BETTER, action, too ! My 6 XC Rifle, is being built on, a New S/ Stl. Rem 700, (Lapped Lugs, etc., but NO, Thread work ! ) and is being built THIS way for, Informal, Fun Target shooting, Steel Plates to 800 yards and Varmint Hunting. The Total Rifle/ Scope etc., will cost me about, $2,000 to $2,500 Max, but IT will NOT be, a "Competition Rifle" as, I'm expecting only, .25 to .500 MOA out of it.
The Rem action and Pre-Fits are "good" for, MOST, "average guy" uses,.. and Budgets !