Actually being limited to under 1300 yards for manual setting on imperial measurements is no problem. If you're shooting from outside 1300 yards with conventional targeting methods you're too far away (I like to be under 800 yards). If you're using the Dick O'Kane technique you don't care what the range is anyway because it isn't a targeting parameter.
Part of effective shooting is extreme error tolerance, especially in a convoy that is scattering. You have to assume that your setup isn't right and be close enough so that whatever error you have is within the allowable tolerance. I've taken shots from 500 yards because I knew my setup was lousy. BOOM! anyway.
