"I would stick with factory loads myself . Nothing like hearing a click from a defective reload when a big tom is 20 yards away.REloads are fine for skeet or dove where a dud dont matter much."
Oh yeah, great advice from someone obviously
NOT a reloaderand talking out of his butt! Instead, peruse the factory 3inch offerings from Remington, Winchester, Federal, etc.
Their 20 gauge turkey (or specialty) loads
combined with proven data from Ballisitc Products should give insight into whats possible reloading your own! I've been reloading over 40 years, and while a 20 gauge will never match a 12 gauge's performance,
Ballistic Products offers load data and components that should interest you. (1 1/8th ounce loads in a 3in hull,
)