The P-223 is built on the PROSTAFF platofrm and has the BDC reticle dialed in for 55 grain bullets at a MV of 3240 fps. Different ammo can be used with Nikon's Spot On Ballistic Program to dial in your specific shooting style. I have used Nikon's PROSTAFF 3-12 BDC extensively last year on my .308 for deer hunting. Entered my shooting info into Spot On and got the distance for each BDC circle. 4:4 all 1 shot stops. Longest 336 yards.