Re: 308 168 smk
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: notquiteright</div><div class="ubbcode-body">My bad,
I was referring to the 168 Amax, it was 2.5moa flatter at 600 yards when shot at an F-class match a few years ago.
I never looked back.
I know several tacticool shooters who swear by their 178Amax loads, perhaps they will chime in with why they selected the Amax over the SMK. </div></div>
I think you have the right bullet (AMAX168) for inside 800 yards. I'm running right at 2730FPS with the chrono 10' in front of the muzzle and this is a really good shooting load for me. The AMAX168 at this speed go to 1,000 yards as well as my best SMK175 or AMAX178 loads do. I have a factory 24" 1:12 twist barrel.
The AMAX168 should not be that much flatter at 600 yards, maybe 1/2 MOA. But maybe you were seeing a little extra velocity from the reduced case volume because you were seating to 2.80" COAL instead of seating to ogive height.
When you seat your AMAX168s try seating them to the same ogive height as the SMK175s and see if they fly a little better. The AMAX168 is a little bit longer bullet and the ogive is a little bit farther back along the bullet's length so seating the AMAX168s to 2.830" COAL puts the ogive pretty close to the SMK175 ogive height with a 2.800" COAL. This is what works for me YMMV but if you have not tried it give it a shot. You will need a comparator of some sort to do this though.
HTH!