I've taken 5 deer with the .45 ACP cartridge.

Taking those deer involved 6 rounds for 6 hits and I've only recovered 3 bullets thus far as three achieved complete penetration.

Admittedly my engagement distances were short (30 yards or less), but based on what I've experienced so far I'd feel OK taking a shot out to 50 yards under the right circumstances.

That self-imposed range may not be the limit of the .45 ACP's effectiveness, but out of respect for the animal and guns I normally use (service style pistols) that's all I'm personally going to ask of the cartridge.

The guns used was a Glock 21, Glock 30 and Colt 1911. The ammo used was 230 gr Gold Dot, 200 Gr Gold Dot +P, 230 gr Winchester Black Talon and 230 gr +P Hornady XTP.