In 1974 I bought my first defensive shotgun. It was an 870 decked out w/ a 20"rifle sighted barrel, an extended tube, a sling and a pistol grip Remington folding stock. I later bought a police trade-in just like it to keep in the office in my shop. "00" buck was my favorite fodder. I practiced shooting large squares of cardboard for pattern. I even practiced shooting clayes (bird shot mind you.)
Over time I decided to lose the slings... They just seemed fumbley and I didn't walk any distance with these guns.
I later bought two Choate synthetic stocks for them as the pistol grips seemed to no advantage and unfolding the stock was just another action that had to come before pulling the trigger. The Choates were also a lot easier on my shoulders.
A few more years and especially shooting clayes convinced me to lose the extended tubes for a lighter easier "snatch to the ready."
Over time I had actually "reverse tacticooled" both of my shotguns.
Rotator cuff and hand problems had me thinking of finding something with less recoil. I bought a used 870 Express youth model 20 gauge with a 20" ramped barrel and a huge aluminum bead. Compared to the 12 gauge models I love the carbine like weight and smaller size. I will agree that with the lighter weight there is still quite a bit of recoil. I'm thinking that with the shorter 11" pull, ramped barrel and big aluminum bead this gun was designed to be easier on the "newbies". I find the gun a lot more pleasant to practice with than the 12's. I quite like the patterning of the 3 buck (2-3/4") with the modified choke. Slugs seem to perform quite adequately from the modified choke if not a little more accurately than the 12 guage slugs out of the 20" cylinder bore barrels.