How are they selling out? What I see is a strategy, the left is calling "ban ban ban" on everything from semi auto weapons, slidefire stocks, magazines etc. the nra sees slidefire stocks as something that is just a mere novelty. That's all it is nothing more and nothing less, it's a good middle ground in my opinion, something that your everyday gun owner more than likely had no interest in having until they found out they might get banned. Would you rather lose your stupid stock that makes you do mag dumps a little faster or all your rifles that are sitting in the safe? Big decisions are like chess Sometimes it's worth losing a pawn to save the king.
And pushing it to the BATFE for "review" keeps Congress from voting on a ban, and what ever else they can sneak into it. At the end of the day, one trigger movement equals one cartridge fired. The binary triggers should have more to worry about than the stupid bumpfires.