Underribs on original rifles and guns are made of folded sheet iron/steel - not cold rolled or machined solid metal. They are attached by a number of means, including soft solder, rivets and small machine screws. For best accuracy, be sure there is clearance between the aft end of the rib and the fore end of the nose cap. In my experience, rifles with ribs are capable of superlative accuracy - I see no detraction from accuracy caused by an under rib. One tip though...be sure to return your ramrod to the rifle before each shot. Failing to do so will create inconsistency shot to shot, and could affect your bullet impact.