A typical .410 slug load consists of a soft-alloy 1/5 - 1/4 oz. slug loaded to about 1800 fps. It's incredibly poor sectional density, soft lead, and blistering velocity means that penetration is sorely lacking, even for bambi. They often literally expand into rings on impact.
WHY!?
Why would anyone load a .410 shell that way? What is the logic behind it? Such a load is only good for close-range, opportunistic shots at mentally challenged coyotes, which anything is good for. Who has any use for a load that basically slaps a coin face-first into the target? Were these loads designed for use as torturing devices?
I don't see why the .410 could not be loaded to duplicate .41 mag deer hunting loads, or at least come close. For the 12, and even the 20 gauge, there are heavy, hard, flat-nosed slug loads available that will shoot clean through a moose from 100 yards and leave a bore-diameter wound channel that will gush blood like a fire hose. Even "normal" slugs in these bores are good enough for deer. Shotgun slugs need weight and hardness, not velocity. The .410 could be an adequate, no, GOOD deer gun if there were decent slugs available for it. Why aren't there any?