I don't think it will. The following Browning website clearly shows the 22" rifled barrel to have a 3" chamber. http://www.browning.com/products/catalog/family.asp?webflag_=027B&catalog_=B Which model Maxus did you get? I recently bought a Maxus Sporting but haven't received it yet.
I purchased a 3.5" Realtree Max-4 Maxus and was wondering the same thing. Browning makes a 3" cantilever rifled Deer Stalker barrel that comes with a new forearm to accommodate a thicker barrel. If not that then I guess a rifled choke is the only option.