I never pay that much attn to grooves and how many etc. Looking to order a Pacnor #1 or mtn contour 6.5 barrel to have on hand and know I want an 8 twist. Only question is 3 groove or 5 groove? Have a 3 groove pacnor in 223 and like it a lot but what about the 6.5? Bullets will be 140 vld to 147 eld-m. Thanks for advice.