What load/kind of pattern are you getting now at 30yds?

I've helped over a dozen friends and family set-up a turkey gun and a .660 Jellyhead has always been the go-to standard for turkey chokes. I've never seen a bad pattern.

Not sure they even make them anymore but I have a Drury Brother's Madd Maxx .665 choke on my 870 Super Mag. It patterns 3.5", 2 oz, 5 shot, Win HV Supremes so good out of my 870 there was no need to even try any kind of hevi shot. I don't shoot a circle when patterning a gun I shoot at a head and neck turkey silhouette. I don't care how many pellets is in a circle but I do care how many are inside of the head and neck silhouette.

I have an 870 and purchased a SumToy choke. They are a custom choke maker. The nice thing with them is you pay for 1 choke and if doesn't pattern well, they will keep working with you and keep tweeking chokes until the gun patterns well. The owner's name is William Lambert, phone number is 912-237-4360. The website is
http://www.sumtoycustoms.com

I purchased a lot of chokes, tried them, didn't like the pattern and then was stuck with the chokes. SumToy charges you 1 time and you will end up with the choke that works best for your gun.
Out of my 870, I shoot HeviShot 3.5" 2.25oz #7 and get 230 - 250 hits in a 10 inch circle at 40 yards. Pattern is pretty even too.

Good Luck