At retirement, Md used 18 and 20" bbled 870s exclusively, and they went to some extended mags as I rolled out the door. I had been calling for same for ten years, but have no idea if I had anything to do with the decision. I favored the extensions as much for extra weight as extra rounds, the troops had trouble dealing with the stock 870s and a few more oz would cut the kick considerably.
When I was a rookie, there were some long barreled WInchesters for the towers. There were 12s, a few ancient but excellent 97s in inventory,and a number of 1200s. The last didn't stand up to the work. All had full length bbls and tight chokes, mostly Full and Fuller(G).
Rhese days, tower guns are 870s, usually Improved Cylinder. Towers are often more than 100 yards apart. Good thing we keep Mini 14s up there also, huh?
And Shawn, I'm past tense,retired Jan 98.
And I take living seriously and a shotgun is a dandy tool sometimes for not assuming ambient temperature. Plus, I like shotguns.
6 for sure, does your nose ever bleed when you touch off that cannon(G)?