https://youtu.be/ZufLsEvmc5E0:55 -- Not a striker fired gun. It has a linear hammer. Something I've decided to be persistent on as it directly affects 922r considerations with this weapon as well as better describes how the gun actually functions.
2 min -- arsenal type 2 brake on the gun. Prefer it to the standard "slovak brake" like at 3min.
3 min are kinggun ambi mag release and tactical bolt release. King gun is best mag release for lefties IMO. And they can cut off the right side tab or leave it. Main drawback of this vs zendl is that it protrudes past edge of receiver which increases accidental mag releases... Why the Czechs originally went from single loop trigger guard to split front trigger guard with mag release protector...
6:30 -- that square optic sounds much the same as a vortex spitfire 1x, but haven't run down its specs.
Not sure what all parts are required for 5.56 vs 7.62x39. I'd imagine bolt, firing pin, possibly extractor, and then probably some sort of improved feed ramp on the receiver.
Less here to note than I originally anticipated.