When both the fouling target at 200 were great accuracy, muzzle velocity obviously comes into play at 600 during the drop test. Certainly could be the yaw, creating additional drag and contributing the additional 7 inches of drop and scatter on the target. I'm no Bryan Litz in this area. I will assure you I'll never know as I won't be shooting these bullets, as well as the 168 Barnes that at 100 yards they are completely sideways, despite the advertised twist ( which was wrong and changed by a full inch the following year). Berger 180 VLD Hunting is wonderful out of this 7 mag.According to Litz, the minimum recommended twist for the 175 ABLR is 1:8.7. You SHOULD be ok with a 1:8.5, but depending on environmental conditions, MV, etc., you might getting into the marginal zone. Just a thought.