If I were to purchase a new drilling, it would be 20 gauge, only because I am not aware of any manufacturer of 16 ga drillings any more. Both my Krieghoff and my Sauer drillings are 16 ga, and the balance, proportions, and weight make them handle like a nice bird gun. The few 12 ga drillings that I have handled felt heavy and poorly balanced by comparison, and too wide in the hand for comfortable one-hand carry.
I am not a fan of the 20 ga. 3" shell, and think it is a ballistic mistake - too high pressure, poor patterning compared to the 16 or 12, etc. BUT in a drilling those small concerns take a back seat to the handiness and usability of a more compact gun. An ideal new drilling for me would be 20 ga 3" IC/MOD steel proofed, over 8x67JRS or maybe 7x65R.
