The Brunswick had a two groove barrel designed to accept a "belted" round ball. Like all rifles of the period, the Brunswick rifle suffered from the problem of being difficult to load. Rounds for rifles were required to fit tightly into the barrel so that the round would grip the rifling as it traveled down the barrel, imparting a spin to the round and improving its stability. Even though the rib and groove design of the Brunswick allowed it to use rounds that did not fit quite as tightly, the black powder used during this period would quickly foul the barrel, making even the Brunswick's design more and more difficult to load as the rifle was used.