RE: with a bow at 20Yards how big are your groups?
GMMAT I totally agree. People over-inflate their abilities when they start talking about their group sizes. They remember the best groups and forget about the majority that make up the true average.
Grab a Vegas target and shoot a 45 arrow round. If you can shoot 1/2" groups at 20 yards, then you are world class. You would have no problem shooting a clean 450 / 45X Vegas round. You should be out there making money with that kind of shooting.
Do you know what percentage of archers can shoot a 450 / 45X Vegas round, with their bow hunting setup? Try it sometime and let us know how it goes.