one point to consider, if you're going to shoot a lot of varmints, is that the .243 case design will erode the throat quicker than the 6mm rem. it's not a problem when the target is deer-sized, but when best accuracy is gone in a thousand rounds, and you are trying to bust minute-of-angle critters, it might get frustrating. if you are starting from scratch, and don't mind working up your own loads, i'd go for the 6mm. but rifle's offered in this calibre are limited. even remington only offer it in the VLS - and i don't think you'd want to lug one of those around chasing deer.