Had A Colt Sporter in x39 and it ran well, zero issues. Not very accurate thgough. I used FankenMags.... 30 Rd Steel AK mags, cut and welded to a steel AR upper. NO idea if anyone builds them anymore.

Back when I could buy x39 ammo for ten cents a rd it was fun. But frankly right now with x39 and 5.56 ammo fairly close in price...I can't see the attraction.

FN in MT