Shooting out of a rifled barrel is hardly a problem. Just don't use shot, rather sabot slugs. Sabot slugs are more expensive than rifled slugs and shot shells, but if you scope out a shotgun with a rifled barrel your range will be a lot farther than with shot. The purpose of the rifling is to stabilize the "bullet", making it more acurate thus enabling it to travel farther.

Brandan