The Remington Model 7188 is a prototype automatic shotgun.
The 7188 was specifically developed for U.S. Navy SEALs for use in the Vietnam War. It was well-liked by the SEALs because of its sheer destructive power, but was said to recoil extremely hard. After the war, most 7188s were converted to semi-automatic operation and designated the Model 7180, despite retaining the unique selector switch.
The 7188 is essentially a fully-automatic Remington Model 1100.
The 7188 used a variety of custom loads, such as the nine-round XM162, the 27-round XM257, standard 12 gauge buckshot and a few custom 12 gauge silenced rounds.
The 7188 had many variants, in fact, six.
- Mk 1
It had an extended magazine, perforated barrel shroud, bayonet mount and adjustable rifle sights. This is the most common version.
- Mk 2
This was identical to the Mk 1, but had a ventilated barrel rib and front bead sights of a standard shotgun.
- Mk 3
It was identical to the Mk 1, but lacked the perforated barrel shroud.
- Mk 4
This was a Mk 3 with standard shotgun sights.
- Mk 5
This was a Mk 1 with no perforated barrel ribs and lacked an extended magazine.
- Mk 6
This was a Mk 5 with standard shotgun sights.