Been trying to dial in my Remington Express with factory 26" barrel that I got a few weeks ago.  After getting the POI changed by my gunsmith with a bit of bending of the barrel its pretty close now.   Anyway, I had several different loads to try with a few different chokes.  The Chokes were a Comp-n-choke XX, Remington factory Superfull (572), Sumtoy chokes, 562 and 567.  Loads on hand and tried were Heavyweight 6's,  Longbeard 6's, Old Remington hevi-shot 5's and 6s and Heavyweight 7's (only shot a couple of those because I'm hoarding them) and some 3rd degree shells I bought at Walmart with TSS size 7's included.
Testing was done at 40 yards checked with a laser range finder and all groups were shot off a lead sled in about 5 MPH winds at 62 degrees.  Barrel was not cleaned as I forgot my bore snake.
Clear winner was the Winchester LB in size 6 with the Remington Superfull turkey choke.   148" hits in a 10" circle at 40 yards.  Second place was my Sumtoy .562 and Federal Heavyweight with 132 hits in the 10" circle at 40 yards.  Either combo was a real dead turkey at probably 45 yards.
I'm done as that's good enough for my backup gun.
FWIW, the Federal Heavyweights in size 6 weren't good for at all.  Averaged about 80 hits.   The 3rd degree shot worse then any other shell, but I only tried it with 2 chokes tubes (my two Sumtoy's). 
I was very impressed with the Long Beard.  I've heard it is good, but didn't realize it was that good.
Picture of the winner.