A combination gun is a break-action hunting firearm that comprises at least two barrels, with at least one rifled barrel and one smoothbore barrel. Combination guns using one rifle and one shotgun barrel usually are in an over and under configuration. Side-by-side versions are referred to as cape guns. A refers to a combination gun that has three barrels. Four barrel combination guns, vierlings, while relatively rare, have also been made. Combination guns generally use flanged cartridges, as rimless cartridges are difficult to extract from a break-action weapon.