I went out and bought a Carlson .568 Longbeard and a Carlson TSS .555 for my compact 870 20 gauge. I already had the factory Rem turkey .572. In my testing, the Carlson chokes were blowing the pattern open with Federal 3" TSS #9. I then decided to use the factory .572 and that was the ticket.
I too just tried to use the bead and mine was shooting ~16" high @ 40 yards. I bought the TruGlo Gobble Dot Pro sights and that was the ticket for me. You could run a red dot with a rib mount if so desired.