I have a Ruger SR 5.56 with a Nikon scope with a custom turret for 55gr. 3240 FPS, I’m shooting Winchester 55gr. Ballistic tips which the box says 3240FPS! I shot through the chronograph today from 10’ away with my average being 2970FPS! Wondering if I order a new custom turret with 2970FPS DOES MY BULLET COEFFICIENCY CHANGE FROM THE (Stated 3240 0.267) on the box Shooting 2970 FPS?? If so what would the new coefficiency be?? Thanks in advance!!