Home Forums Hunting & Shooting Ask The Gunwriters Help me understand the relationship between velocity and seating depth

This is what you should get. The initial drop in pressure and velocity as you move off the lands is due to the ease of engraving the bullet with a running start. The increase past that is due to loss of case capacity/smaller starting volume.

The magnitude of the two effects changes with bullet diameter, because the amount of case capacity lost per distance set back increases as the square of the diameter.