Recent build we did for Battleborne in Mesa AZ. Local doorkicker needed a compact breaching shotgun and the setup from Royal Arms was unnecessarily bulky and heavy so we set him up with a custom Mossberg 500 build with a KA-1212BR breaching attachment. This gun was being built to hang from a single-point for easy deployment as needed so keeping the overall size and weight was a major consideration.
The barrel was shortened to 10-1/2" and the KA-1212BR was installed for an overall barrel length of 12-1/2". The barrel lug was reinstalled directly behind the breaching attachment. Although we could have resized the lug and installed it directly to the KA-1212BR and picked up an extra round in the magazine, this would have added more weight to the gun and the department prefers blowing the door hinges rather than the lock so this configuration is easier for performing a "top shot" on the upper hinge.
The magazine tube was then shortened and the cap silver-soldered back into the tube. An S&J Hardware delrin follower (part# SJ-RM01D) and shortened Wolff spring was installed.
The action slide tube had about 2-1/2" removed from the middle and the two pieces were carefully TIG welded back together and the weld was turned flush on the lathe. The forend was then miter cut and resized to fit the shorter action slide. This results in a "factory" looking forend that is shorter to fit the shortened magazine tube.
The entire gun was sandblasted and parkerized by AZEX and finished in matte black Duracoat by King Armory