In 9mm the 105gr Gaurd Dog behaves and performs just about like most 380 ACP.
IIRC 10-11" of penetration - 12" max I believe and something liek .50" - ish expansion.
I don't see why someone would use it unless maybe they had a derringer in 9mm and couldn't handle the recoil so instead of buying a different gun they download it with Gaurd Dog EFMJ ???
I'd look at the gel tests for .45 to judge it, but if you look at the Winchester Ranger T in .45 I don't think over-penetration is an issue. The 230gr Ranger T is penetrating from 11" to 12.5" somewhere around there. Are you worried about overpenetrating misses? or overpentrating an assailant?