Contradictory Issues?

[tlbaker]

The bolt is a Monster MK136. Compass Lake did the Criterion barrel and matched bolt. My velocities have always been ~200 fps higher than Hornady gas gun data. My assumption was the slower powder continues to burn and increase pressure after the bullet passes the gas port. But I would also think this show in the ejection pattern as overpressure.

Alpha brass is not cheap so I don't want to destroy it.