Another nut option is the Shilen Alternut;
Products::Rifle Barrels::Alternut Replacement Barrels
Alternut
Drop-ins.
After numerous customer requests to design a drop-in barrel for the Remington Model 700 Shilen has done that and more by designing their NEW patent pending dual threaded
Alternut System that will bring the ease and flexibility of drop-in barrels to even
MORE platforms.The dual thread system was designed to increase the barrel diameter and wall thickness at the chamber end while still using a lock nut. To make things even easier for our customers these many configurations may use a Large Shank Savage lock nut.
Alternut barrels come threaded and fully chambered to be installed into the action with no additional machining or modification needed.
http://www.shilen.com/alternutbarrels.html