Neck length adds to the OAL to touch the lands. I have made up for this by short chambering the 22/250 AI, .025 short. You crush the shoulder back with your full length sizing die when you are pepping your cases for fire forming, this makes the necks grow in length.
My reamer also has zero freebore, puts the 55g Nosler BT bullet shank/BT right at the shoulder neck junction, and the 50g BT base of the bullet right at the shoulder neck junction. 60g Sierra's still shoot tiny groups at 3700 fps in the 12T barrel.
