my mossburg 500 likes the Carlson's turkey choke, unreal tight patterns at 40 yards, using Rem 3", 41 pellets of #4 Buckshot, my barrel is 28" long, gun is a pawn shop special $135 beater. Have a 11/87 and 391 also, both pattern better at 50 yards with the turkey choke with #4 buck shot...never tried heavy shot.
I would encourage all to pattern their shotguns at 40 yards as a "benchmark" as this is really not very far. Then when you have determined your choke that works best, try the 50 yard pattern...
I found a long time ago to use a set of shooting sticks or bench rest to test the guns pattern and point of aim vs impact...eye opening to say the least.
I consider 30 yd pattern boards as ego boosters, real world is 40-65 yard...so, get real!
Note: 3" mag 12ga gas operated auto's are real easy on the shoulder along with recovery time vs pumps and others.
I hunted with two 10ga Ithaca 32" gas operated auto's that would shoot coyote to pieces at 60 yards with 2 1/4 oz of Copper plated BB's. I killed several coyotes in the 70-85 yard mark with 54 pellets of #4 Federal buckshot. The 10ga swings slow, and is a wicked field gun...a Real Man's Shotgun for sure!