Re: .308 SMK + 300RUM - 190, 200 or 210g?
What do you intend to use this setup for??
If its varmints youre after DO NOT overlook the 178 AMAX. Its alot flatter than its published BC at 300 velocities will lead you to think. Aside from that and if the range is 800 yards or less the 190 SMK has always been a favorite of mine. They can be launched faster than the 210's and 220's. Out to 600-800 yards next to the 178 AMAX theyre tough to beat.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.