We created this 5.56 as a counterpart to our .300 Blackout. It operates in conjunction with our Crusader lower-receiver illustrated therein. So it still utilizes the Franklin Armory: binary-trigger feature, as well as the same KAK Industries: Shockwave 2.0 wristbrace.
The reason for this design was that we wanted to provide the shooter with an ability to swap calibers, and quickly expand their range. Thus, we produced an upper which includes a 10.3” barrel, chambered in 5.56, by Expo Arms. It has a SOCOM profile with a 1:7 twist; therefore it’s stiffer, and more ideal for heavier grains such as 62 or 77, instead of the typical 55 grain round. Thus, the shooter can now expand his effective range out to 400m; well beyond the capabilities of a .300 Blackout.
For all intents and purposes, this upper assembly required something more appropriate than a red-dot sight however; therefore to facilitate hits, we equipped it with an optical upgrade as well. We mounted a Vortex: Strike Eagle 1-6x24 combat-optic; which includes an illuminated reticle containing a bullet-drop compensator. The tip of the post represents 20-200 yards, and each stadia-line progresses down to 600 yards finally.
The muzzle break on this weapon, is that of the Springfield: Saint (pistol); which is actually a blast-forwarding device. We felt that not only would it redirect emissions away from the shooter because of the shorter barrel-length, but also that, aesthetically, it paired nicely with the end-cap we used to secure our Bravo Company Manufacturing: PKMR handguard.
The PKMR (Polymer Key-Mod Rail) by BCM was designed to be utilized with a Mil-spec front-sight post, and fastened by a delta-ring in the rear; yet because we were set on the appearance of the BCM pistol-grip and PKMR combo, we stepped-up to the challenge and improvised a means of attaching it. The PKMR is a three-piece design, with two side-rails connecting on top, and a single bottom rail. The front-end of the each side-rail secures to an end-cap over the barrel, by using two small screws at the flanks. A third screw on the bottom-rail, toward the rear-end, attaches it to the barrel-nut, just like a free-floating handguard does; while the top and bottom rails snap together (by design) at the rear-end also. This provides a solid hold with flush mounting-points; so theres no awkward interference with hand-placement during operation.
In sum, we have uniform furnishings, for a formidable little pistol, measuring-in at just 26” long! (Consider it a Boogaloo-blaster).
This is the BMRCo: 5.56 Pistol.