Didn't say the .380 was ineffective. Just saying that don't expect equal, consistant performance, in a messy situation as you might receive on a deer, with any handgun caliber. Seen enough of both to know there is a BIG difference. A .380 is about like a .38, with the exeption that heavier loads are available for the latter. And I would be hesitant to compare anatomy structures between an attacking felon and deer. Measurements are one thing, but so are tissue and bone densities, muscle, fat, and angles. My girlfriend's Rotweiller is 90 lbs but it aint nothing like a deer.