John Satterwhite once showed me his 870, modified as follows:
Converted to operate like a Model 12 (Holding trigger to rear allows gun to fire as it locks into battery.)
7-round magazine tube, with barrel cut off to just in front of the tube.
Barrel threaded for screw-in chokes.
Half-size front bead sight.
Vented rib.
Dovetail cut in forward part of chamber area of barrel, through rib, and a Williams folding rifle-sight installed.
Either side of the rib, and just behind the choke, were two rows of (as I recall) eight holes of about 0.060 inches, serving as recoil compensator. (32 holes in all.)
Stock fitted to YOU!
His thesis was that the balance of the gun, with only three shells loaded into it, was the same as a 26- or 28-inch upland gun. With cylinder-bore choke installed and the sight erect, you had a slug-gun for deer--or whomever.
He commented that the stock is the rear sight, and you shoot a shotgun much as Jeff Cooper shoots pistols from the Weaver stance. (I never was worth a hoot with a shotgun until after I took up IPSC in 1981. My bird-scores jumped up tremendously!)
Satterwhite can throw seven claybirds at once, by hand, and shoot them all before they hit the ground. He was a PanAmerican Games Skeet/Trap winner a time or two, and on the US Olympic Skeet/Trap teams a couple of times. When a fella like that tells me something, I tend to believe him...
Anyhow, some points to ponder. Good shooting!