I need some idea for load(s) for 243 for 600 yd shooting. Never having practice that far im unsure as to what load to be using and what distance to be zero'd at..?? Also have to shoot a 300 yd session prior to the 600 yd squad.... The 300 I think I can handle A-OK but 600 is a tad more than my normal , usual distances. 243 Win in a Rem 700 VLS; Zeiss 4.5-14 scope and a 15 minute rail on the rifle.