A drop in 2 shot AR trigger pack will be available in May for $479. Little pricey but should sell well to the arm chair what-to-be's. The trigger fires on the pull of the trigger then the 2nd shot is fired when you release the trigger for the normal next shot.
https://www.gunsamerica.com/blog/fo...hs-echo-trigger-fires-rapid-fire-double-taps/
https://www.gunsamerica.com/blog/fo...hs-echo-trigger-fires-rapid-fire-double-taps/