Different airlines have different rules. Generally, you have to have a locked case. Get there early and don't forget to declare the gun AND the ammunition.
Going to Canada is a whole different ballgame.
I don't know a lot about the M2. The M1 is my duty/home defense/vacation/potential dove gun. I don't think an 18.5" is any good for ducks though. As far as coyotes and deer? You'd have to be a pretty good slugger I think.
Thanks, guys. I should have mentioned that I'd be more comfortable with a factory Benelli. The speed feed doesn't have a sling attachment. Plus, I generally don't trust aftermarket stuff.
I have a 16.5 inch length of pull. All shotguns used to cause me discomfort. I just threw on a 5 dollar slip on pad and that changed everything for me on my M1. I love to shoot it now. Slugs don't bother me a bit. Have your LOP measured and equip your long gun accordingly.