ORIGINAL: fechmupbud
I keep a full in my 28" 870's all the time. I'm either gonna hit em, or not. Sailing birds in a tidal marsh can be a nightmare - hard on the dog, me, gotta get the boat now, birds working in and I'm not in the blind cause I'm chasing this damn cripple. Hit or miss, that's what I believe - and it gives you extra stopping power on the long shots.
To answer your question, I personally think a mod is fine for most any hunting condition, it's actually what benelli recommends as the tightest choke on their guns for hunting situations.
I'm in the same boat with this guy! My full stays in for waterfowl. I got a snow and 2 blues today at about 25 yards with the full and 1625 fps kents.