Mightyman,
I shoot BH209 and have shot over 30 rounds at targets without any change in P.O.I. However, after a sesion on the range, I always clean the rifle.
When hunting, I ALWAYS foul the barrel with two shots and hunt the complete season/s, regardless of the number of deer harvested or, times shot. The only exception would be, if I fell in a creek or got caught in a down pour. But please understand, this is with BH209 and not Pyrodex or T7. Prior to BH209 becoming available, it was very different except for the fouling shots.