The best advice is to experiment until you find a pattern that works, and stick with it. Chasing the "best pattern" can be somewhat akin to alchemy. Don't make yourself crazy.

If you have some friends with spring fever, share the cost of a few diff boxes of turkey loads (diff mfgrs, diff shot size).

An easy and quick test...set a coke can on a stick at 50yds. If your gun/choke/load combination can take it out, you're good to go. A friend tested his NEF single shot 12ga with a NEF/HR turkey choke on it like this...with Win. Supreme 3" #5 it's potent! (and recoils like a mule)

AND, keep your shots at or inside of your max range. If you can't bust'em past 40yds, wailt til they're closer.