Ciener Ultimate Over/Under
The Cieiner combination offers the opportunity to have both available as and when necessary. The Ultimate Over/Under consists of a Remington 870 pump-action shotgun attached beneath the Colt AR-15/M16 rifle, utilising the bayonet lug as the basic fixing point. A bayonet lug adaptor is attached to the shotgun barrel and a yoke adaptor to the receiver. This adaptor engages the ends of a special upper receiver to a lower receiver hinge pin. The bayonet lug adaptor has two spring pressure clips which fix the shotgun in place, allowing its removal by simply squeezing the clips.
Information from: Anon but apparently lifted from
Janes Infantry Weapons