GR. % performance is relative to the bird hunted for most people. I don't worry about it by and large.

A famous ruffed grouse shooter used 1.25oz of 9's for something like 10000 birds killed. He must have had a dental plan.
People use what they have confidence in.

I do worry about ricochet's and chasing cripples all day.
It's a waste of dog time on the ground.

Out there doing it best I can.