Like all my favorite now dead gunning mentors (from reading their books: George Bird Evans, Nash Buckingham, Paul A. Curtis, Ray P. Holland and others as well of those long-gone generations, I am a 12 gauge man- The other gauges are fine I suppose, (except the .410 bore guns) but I'll take a 12 sidelock with RST light loads (L.C. Smiths are my vade mecum)DT, possibly ejectors-- except for waterfowling and steel shot- then a Model 12 is my choice-

"The field is the touchstone of the man"..