06-19-2012, 09:07 PM
That looks exactly like the Hornady factory 123g Amax ammo that is fired from my rifle; flat primers, light ejector/ extractor shadowing. 24" 6.5 Grendel SAAMI chamber. I don't believe that you can adjust for this with an adjustable gas block. The shadow is created instantly as the projectile fully engages the lands and groves of the bore and gas pressures peak. This event is occurring before the projectile has moved past the gas port.
