I had great success shooting Peacocks at the base of the neck with .45 airguns, they drop on the spot.I agree there's no need for overwelming power, I think a Seneca .45 Twin tube is in the 200-250 FPE range stock and with a .457 EPP/UG it will cut a great, clean hole without blowing through to fast. ( there was a lot of talk back in the day on Adventures in Airguns about the benefit of having a projectile not go past to fast )I definitely go for a .45 for a one gun fits all.
Anyone ever hunt the land called "triple N ranch" near Melbourne FL?