You're telling me this distance is 30 inches on an average goat?This is an average sized BC billy.
The head on my axe is 10 inches.
He was 3 of those through the chest.
So...30 inches through the chest
Goats are not bullet proof, nor are they hard to kill. shoot straight, with a good bullet in any normal cartridge and youll be fine.
But the fact still remains.....4" of penetration isnt much....regardless of what you wife says....