I am getting ready to order my first ever custom barrels. I'm going to order a 20" heavy varmint contour 1 in 8 twist .223 a 26" heavy varmint contour 1 in 8 twist 22-250 and a 26" heavy varmint contour 1 in 8 twist 6.5x55 select match barrels from Shilen for my savage actions, and plan on using 75 or 80 bergers vld's(unsure which yet) and some 55 NBT's because I have a bunch of them for the .224's and plan on using 140 berger vld's for the 6.5x55. These are going to be mainly for long range hunting rigs and informal(For now)long range target shooting useing Winchester brass for the .224's and lapua brass for the 6.5x55 but would like to be able to use winchester brass if lapua is not avaliable. The question is about throat length what would be the optimal OAL of the cartriges and What would be the optimal neck diameter for each.