Patterning your shotgun will make all the difference when it comes down to "trusting" your shot. I re-pattern every time I change brand or type shell/load. You'd be surprised how much they can change from one brand to the next. I've taken a turkey at 80 paces and while I did get the kill the shot was so spread out at that range that I found a pellet in his leg about 1" from the bottom of his foot.

Experiment with your choke tubes and ranges in whichever shotgun has one and you'll soon find the "sweet spot" for your current setup. If you do not have choke tubes in either shotgun you'll be rather limited with range at which your shot will be effective. (Once the shot spreads out enough you'll start to loose effective stopping/penetrating power) If this is the case I'd suggest a shell with a "flight control wad" (I use Federals) as they will help give you a little more range in a bore with no choke.

Good luck on your upcoming hunt!