hi thelaw -
i have a 28" 12 gauge synthetic pardner with a screw in X-full NEF turkey choke. the gun is light, kicks like a mule, but patterns well with 1 1/4 oz #4's in remington premier shells with red AA field wads. i think i used blue dot powder, i'm not sure, but can check if you want.
i have used it for turkey hunting twice, and shot only once at a turkey. obviously, that turkey was wearing body armour or a force field belt because he strutted away unscathed.
the load was worked up from the bench using one of the powder makers data books. i used a cardboard target and ran the velocity up to just before i started to see a lot of flyers. i think i ended up with 1325 fps on the chrony which is pretty fast for such a heavy load.
factory loads, like the 3 1/2" 'guns of navarone' hi brass shells kicked like dickens and did not pattern as well as the hand loads. the hand loads were worked up on a MEC single stage press.
i am sure you will have much better luck than i with with those turkeys this spring !
sg