Rangefinder...
I agree about the alloy being a major influence... I plan on casting very soft. Let's face it... at 850 fps or so, you could probably use pure lead with no problems.
I just have heard nearly all my life about the very poor performance of the round nose 38's... so I know that a big square front (meplat area) is probably going to be a big factor, as well.
Wadcutters may be the ticket. This isn't ever going to be a long range target kind of thing. Probably 15-30 yards would be the most I'd ever be doing while out meandering in the woods.
Plus, if I could HIT a rabbit/skunk/whatever at 30 yds with a snub, I'd be borderline amazed...
I imagine most targets will be those sneaky, dangerous horse apples...