On Remington 870 barrels the middle bead is ALWAYS placed one post a head of the part that hangs below the barrel to slip it on on the tube, NO EXCEPTIONS. If you place it somewhere else it is different than a standard trap barrel.
That Tron said made sense to me, but I know that Senior Smoke knows 870's forwards and backwards, then EdSy agreed with Tron So this got me off my butt and I checked all 3 of my barrels.
I still have the Rem 870 wingmaster I started shooting Trap with. Mine came with the 26 inch Skeet barrel and the 30 inch Trap barrel both factory fixed choked. I also bought one this website a older Modified Fixed Choked 28 inch barrel from a gentleman on this site.
Answer is----------- Tron and EdSy are both WRONG!!!
All the barrels are as Steve B. said. ALL MID BEADS ARE INSTALLED IN THE MID OF THE POST ONE POST FORWARD OF THE BARREL RING.
I also measured all 3 barrels and Tron's placement of one post forward of middle, was only correct about the placement on just one barrel length, the other two would have been installed wrong!!! Sorry Tron!!! break em all Jeff