The #4 doesnt penetrate quite enough for HD, the 00 and 000 a little too much. #1 or #2 would be just right. I haven't gotten around to getting any, so I will make do with 0. More pellets is an advantage, and it penetrates enough, so nothing lost. As for why load buckshot/slug/buckshot/slug as I do, it's because the first shot may be hurried, so a spread is desirable. The second shot will be aimed. The next buckshot round is for an additional threat. If I somehow forget where I'm at in the progression, I doubt I will be the one suffering. I would rather have more rounds, so I don't use magnum loads. Just overkill IMO.