Trained with and shot these alot in the military and out....Forgot how much I loved them.
AAC Striker II 3-lug is pending. New MP5A3 demilled/cut and installed on SW receiver. Pricey, but worth it.
Put 600 rounds through it Saturday/Sunday. I can't get it to malfunction. In words....a dream. Have Surefire 628, B&T lowpro mount (for Aimpoint) on the way.
Best alternative to shooting expensive 5.56/.223 I can find.