Weak scopes riding in weak rings on a weak mounting point are not a positive to wish for.
Pic rails with Pic rings are a vast improvement for reliability and durability in keeping a scope in place. An integral Pic rail mount is even better. Wish more manufacturers would offer it, but it significantly increases the machining cost over the R700 round tube receiver. The integral Pic rail mount is one of the single best improvements in this design for a hard use and/or heavier recoiling rifle. As others said, it one less thing to go wrong.
I'm ready to buy and give it a try, if and when they turn them loose in the wild.
What is the advantage of a .338 Win Mag? The big .300's, Win Mag, PRC, and RUM fill the role for lighter bullets on one side and the bigger .338's best it on the other. A .338 RUM or Lapua runs off and leaves the .338 Win Mag in the rear view mirror.
