I don't know if I can answer your question. But after shooting and building FN's, Imbels, and L1A's over the past two decades I can personally say that the weapon has no weak points. It is well balanced and ergononicly designed, has an adjustable gas system, a fairly heavy bolt carrier, matched perfectly to a strong recoil spring. You can shoot hundreds of rounds through it with out getting a sore shoulder. Kinda has a pogo stick feel. The only drawback I see with it is it's weight.