that was using Chrono #'s. i am shooting a 30" Beman Realtree MFX 340 at 270 f.p.s. i was figuring the arrow at 340 grains not including the knock, insert and blazer vanes. then i'm adding a 100 grain tip which brings me up to 440 grains. finally i was just adding a few grains for the vanes, insert and knock.