Yup, it's all legal. At least in my state.
Well, the Mossberg and the Remington 870 are kinda a little hard to compare simply because there are sooooo many types and builds of those to shotguns. As for the Benelli Nova Tactical. They are the GLOCK of shotguns. Light weight and super cool. Only catch with them is the diesgn of the stock/receiver being one piece. Really can't change it. Hence why many folks still go with either a Mossberg or a Remingotn.
If you want to go a little old school, might I recommend a Winchester Model 1897 Trench or Winchester Model 12 Trench. Ypou can mount a 17 inch bayonet on them and hit folks from across the yard.
Anyways back to business here.
The Mossberg 500 is a good shotgun but it's not a military shotgun. If you want a military shotgun. The Mossberg 590A1 is the true militart shotgun. Remington never submitted the 870 for the combat shotgun trails for one reason. Business, they had nothing to gain but everything to lose. If the Remington lost out in the trails to Mossberg, it would have been over. But since they didn't they never lost any face with the public at large. Also, after the trails. The military still bought Remington 870s for combat use.
Here is a good page about the two best shotguns on the market right now.
http://www.tacticalshotgun.ca/conten...e_870_590.html