[MENTION=25212]Papagrizzly[/MENTION] pretty much hit it.
I have a switch hitter setup on a Surgeon 591/R. Since I have an integral lug, and the barrels have already had their headspace set to the receiver by the gunsmith, there is no need to re-check headspace or use any go/no-go gauges after switching barrels.
Here is my procedure:
- Ensure rifle unloaded
- Remove bolt from receiver
- Remove scope
- Remove BA from stock
- Set BA in barrel vise, as close to recoil lug as I can get. I use a Tubbs 2K vise held down with 2 "c-clamps" and put strips of leather that I cut from a belt all around the barrel to preserve finish.
- Insert action wrench (I use a Surgeon action wrench) in receiver and attach to torque wrench (I have an adjustable 0-150 ft-lb torque wrench w/ 1/2" drive socket)
- Pop the action off the barrel and carefully unscrew the receiver
- Set new barrel in barrel vise
- Rub a small amount of nickle anti-seize onto barrel threads
- Screw receiver onto new barrel
- Torque receiver onto barrel using action wrench (just need to go snug, no retard strength ... you are metal to metal; Surgeon and Gap go 90 ft-lbs on their torque wrenches; I go less)
- Reassemble BA into stock
- Put scope back on receiver
- Install bolt in receiver
- Sight in at range
Hope this helps.