I just patterned a few more rounds thru a new Comp-N-Choke modified choke I put in my 18.5" tac 870 this morning. The Remington 2 3/4" still blows everything else away, holding 20" patterns at 32 yards) there is a landmark at exactly 32 yards so I've been using that distance for comparison a lot. I haven't found anything better in a 2 3/4" round for my particular gun.
Malfunction drills? I run Glocks and AKs so I don't have to bother with that stuff.