Re: Sierra 6.5mm 123 gr MK, why are we not using it???
I think the reason many have moved away from the lighter bullets is because we no longer find super flat trajectories useful with the advent and availability of laser range finders. For hunting, it becomes a sectional density and retained energy game. Less windage as well. I can get 3000-3100'sec with 155 grain bullets in my 308s too but the numbers at 1K for hunting just are not there. Windage, energy etc...the trajectory values are impressive but wind and energy + penetration not so much. 190+ and now we're in buisness. Sectional density and BC wins. Compare a 168smk at 3500'sec versus a 208 amax at 2600'sec. The only advantage the 168 at 900'sec more has is a flatter trajectory. Wind and energy goes to the 208 even at 900'sec less starting velocity. My question here is, with a cheap reliable laser rangefinder, who cares about trajectory?
Long range shooting is a process that ends with a result. Once you start to focus on the result (where the shot goes, how big the group is, 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.