Our Signature Model Gen-12 was based on the DPMS gen1 308s. We made some changes to the lower look but the models shared very close specs. We had received so many inquires to make a stand alone upper offering, we decided to make some cosmetic and we made some enhancements.
The upper is a synthesis of all the good from our GEN-12 SM. Now it can be mounted to your compatible DPMS patterned gen1 308 lower receiver. We know other receivers will work, but it will wholly depend on how close the company, producing the lower, remained to the DPMS spec. For example this mounts to a Aero Precision M5 308 receiver, but not the SLR 308 receiver (we plan to cover compatibility in another article).
Enough of this rabbling, so lets get to the details of what you get with an upper.
The upper and hand guards are machined from billet aluminum 7075 and 6061 respectively. Everything has been anodized to milspec industry standards. The standard rail features MLOK at the 3, 6, and 9 o'clock positions with a full length picitanny rail at 12 o'clock.
There is no gas pistons or tubes to service or used to regulate gas. The Gen12 can run both 3" and 2 3/4" 12 gauge shells. The majority of testing was done utilizing the DPMS short buffer and spring in a standard AR15 buffer tuber. The longer 308 buffer tubers (or A5 length) can also be used, but we had some limited testing with this setup. If you are running the longer length buffer tube which runs the AR carbine buffer length, then we recommend you start with the H1 or a H2, and see which works best for your application.
During our testing and evaluation we were not sure how the upper was going to perform on accuracy. Our primary focus had been on function and reliable cycling with a variety of shell loads that we just had not put much time into accuracy. The GEN12 had been run in some local 3 gun courses and we had done some unsupported shooting, but nothing to tell us how accurate it was.
We got serious with accuracy in August of 2017 and took our prototype upper to get a 50yard grouping. We shot it using a Larue 2 stage trigger on a GEN1 DPMS 308 lower (seen above). We used Federal Truball 2 3/4" rifled slugs and measure our 50 yards with a laser range finder. The shells were fired from a tripod in the standing position. The 5 rounds were fired consecutively and the first group was 3" all rounds touching in a horizontal string. This video was taken in 1 take, and we have repeated the grouping many times since.
We stand by our product. We have shot 10's of thousands of shells out of our original gen1 Gen12 shotguns. We have run near 10,000 out of our prototype gen2 Gen12 upper. We between generations we have made some mild changes which will increase reliability and longevity. Based on our T/E of the prototype we anticipate a heavy shooter to run an upper for thousands of shells with reliable function.
The challenge still remains of accommodating the variety of shell manufactures. We have found depending on the manufacture and the lot which the shells were produced can greatly affect reliability. We plan on putting together another article on shells in the future but until then this is our disclaimer: not all shells are created equal. Test your shells in your upper and running hotter is always better. However, it is our goal to get our upper dialed to run the lightest of loads then turn around and shoot the hot stuff! More on this later.
Final note on longevity, both for the shooter and your weapon. The Gen12 was designed to run all shell sizes and loads on the standard short DPMS buffer; however, this is not recommended. As for some of the magnums you will not the bolt to hold open on the last shell and your shoulder will take a beating. We recommend running heavier buffers or the hydraulic buffers when running magnums or hotter shells. So take that for what it is worth
This is biased. There has never been a true AR 12 gauge shotgun. We are bringing a 1st to market. It has been a challenging road. It has only been through our crew's dedication, resilience, and will to succeed that we have come to today. We are continuing this endeavor with high capacity magazines, barrel options and maybe eventually more models in other popular shell offerings.
Until then, we are confident the Gen12 will quickly become one of your favorite guns to shoot. Nothing compares to a shooting a 12 gauge with the ergonomics of an AR which all equals great fun!