I shot a TC renegade probably 200 rounds or more testing this and that for elk loads... and yes I"m a hair OT...
Would shoot about 4 inches best case at 100 wiht irons.
I sent it back to them.
They sent it back with a fired target, about 4 inches at 100, saying it was working perfectly and grouping fine...
Promptly bought a green mountain tube, and was down right at an inch wiht 565 grain slugs and 100 grains of powder... no tinkering require....