I shoot a Nemesis Windrunner. I have a 308 barrel and a 243 barrel. When I switch barrels, my point of impact is about 6" low and 6"left. Its pretty consistent. Will it be more consistently accurate if I have separate scopes for each barrel, or just zero for one barrel, and adjust the scope to be on target with the other barrel. I already have a spare (similar) scope. Any consensus.