120 class powders

[Klem]

What I was saying is that positional factors can manifest as erratic muzzle velocity.

Surely not to the extent of Dt's graph.

We were talking about internal ballistics but as chonographs are technically external, I accept we can influence readings by working with, and against gravity (pointing the barrel to the sky or to the ground). Or allowing recoil to rob some velocity (by permitting the barrel to move rearward) at the time of firing. But all these influences are negligible on muzzle velocity. Group sizes for sure, but muzzle velocity surely not.