It's funny you say that, we had 2 guys in our squad run Galil Ace's. One 556 and one 762. Both of them had failures all 6 stages. The charging handles kept hitting cover and getting caught on their slings.
Anybody having reliability issues with a KNS piston swap? Mine has had to be re adjusted every time I take it out. It's in a 16' 5.56 polish WBP that didn't have any issues before the swap