Nothing special is needed for Turkeys - a nice tight choke and a little camo wrap or tape makes a nice turkey gun. I have an 870 thst eillvdhoot fsncy magnum shells with a turkey x -full choke and a sling but i always end up dragging out the old model 11 and 2 3/4" number 5's. I thought this year's gobbler was at my max range of 45 yards when I shot him pretty quickly before he walked out of range. With a little more time to measure he was well over 50 yards. That is with a 50 year old shotgun and walmart ammunition.
So pick the shotgun that fits you best and give it a turkey season makeover. Knowing your pattern and how far you can count on lethal density is what you want to use as your guide.