I am not a fan of the NEF Handi, the reasons are well documented here.
That being said, when I ditched my rifle barrels, I kept my huntsman, because it shoots terrific, and is a great deer rifle (sb2 frame). It is of course d&t'd... Get the factory rail! I also mounted a scout scope as far up front on the rail as possible. For me it is the ideal most forgiving muzzleloader. 90gr 777 295 pb.. Don't care what primer... It's set up exactly as I'd like... So it only shoots deer!!!! I took the rod and mount off the gun, and put the rifle forend on. Hollowed out the the screw hole with a small rat tail, and made the thing even more accurate....