RE: What's your Duck Gun?
My main squeeze is my Beretta 390 Silver Mallard... I usually shoot a Briley Extended IC or LM.
Other main gun is a circa late 70's Rem 870 Wingmaster Mag. Has Briley Thinwall chokes, and it shoots well with an extended Mod choke.
For the very nice weather days and walk in hunts.... I'll occasionally tote my Browning A5 16ga (standard, not sweet). Or my Ithaca SxS 20ga. Still have some Kent Tungsten Matrix squirreled away for my old guns!