Thread: What could cause this?

For what it’s worth,
I didn’t have a chrno, plugged all ambient figures I could get from met service, elevation from topo.
And took away 25fps for every inch of barrel chop. Based on a 24 inch starting barrel and box velocities.
I was pretty happy.
Based on the data I dropped my speed a little for each. ~25fps for each rifle. Can anyone say if that was a mistake? I didn’t verify that change because I was sick of walking and needed to get home

Also, I used spirit level on target and on the barrel when it was on the target to ensure There was no shooting angle