Re: .308 HDY A-MAX 178 Data?
You sound like you are marching down the same path I've been down. I tried the 168 SMK. Great at 100, but overstablized in my 1 in 10 twist barrel past 600 yards. I went to the 190 SMK and found it is real happy to past 1000 yards, but I can't get it to expand at .308 velocities, so it is out for hunting. I spent a small fortune on developing the 178 A-max for hunting before I found the combination that worked in my Savage. What I discovered is that this bullet wouldn't work with any published load. Since I wasn't seeing any pressure signs I bumped the load up and the groups started getting tighter. When I reached reasonable pressure limits I experimented with overall length. I found that my rifle likes a load with 44 grains of Varget with the bullet in the lands a few thousandths. This is the first load with the 178 A-max that produced acceptable groups, and they were under .5" at 100. I went on to the 180 Accubond before I tested the A-max beyond 100.
I found the 180 Accubond likes Varget. I tried everything from 42 to 44 grains and had the same group. I experimented with COAL and found that the Accubond wasn't particularly sensitive to seating depth in my rifle. The groups aren't phenomenal at 100 yards (.75"), but they will hold that group way past 300. I do intend to go test the A-max at longer ranges, but I figured that any bullet that is that sensitive to muzzle velocity changes will have a smaller range of accuracy down-range, as velocity is dropping off. Only field testing will tell for sure.
Attitude is EVERYTHING!