Yes they are.
Eliminating any other factors, I guess the Bullseye spiked higher. My guess is early in the curve. The latest burn rate charts do not list WW540. I believe it is the same as HS6. Ball is going to act a little different than the other flakes as the loads get hotter. WW231 will act more like Bullseye, but Bullseye might be more predictable in that case form. Long narrow case with higher sectional density bullet than what WW231 is normally used for. Just thinking out loud.
