If you want a high capacity, semi-automatic tactical shotgun feeding from a box magazine, the Saiga-12 is pretty much your only option. Ho hum. But wait, a challenger appears!

Intrepid Tactical Solutions is releasing the AR-12, a 12-gauge shotgun upper that fits on standard SR-25/PMAG type AR-10 lowers. The upper is piston driven. The user must install a stouter, shotgun-specification recoil spring in the buffer tube, but otherwise the lower half of the gun remains the same as an AR-10. An 8-round single stack magazine has been designed to fit in the big AR-10 magazine well.

The genius of the AR-12 may also be its downfall — proprietary ammunition. Traditional 12 gauge ammo doesn’t get along well with box magazines due to the rims of each round stacking up against each other, and there are other complications as well. Ask Saiga-12 owners and they will tell you about the long, hard road to getting one of those guns to work reliably with cheap, low-brass ammunition. Intrepid went outside the box and designed a new, all-polymer 12 gauge round that resembles a scaled-down 40mm grenade, with a rebated rim, round nose cone, and “payload” area containing the shot. This new RAS-12 ammo is said to be key to the AR-12’s reliability and terminal ballistic performance.

Intrepid claims that they have a deal with a major ammunition manufacturer to produce good quantities of high-quality ammo for the AR-12 system. This manufacturer has bet that a certain market segment is willing to move on from the 100-plus-year old standard smokeless powder 12 gauge shotshell and bring the tactical shotgun truly into the 21st century. However, bigger companies than Intrepid have recently tried and failed to introduce promising new cartridges to the US market (a lonely 45 G.A.P. Glock collects dust in the “Used Firearms” display case at my work, mute testimony to this fact). A striking number of American shooters absolutely refuse to buy any gun requiring ammunition not normally stocked at Walmart.

Is the new RAS-12 ammo the next big thing? Or will it go the way of flechette ammo, the CAWS prototypes of the 1980s, and so many other bright ideas that simply never caught on for one reason or another?

Thanks to T.G. Moore who sent in a tip for us on this one!