Ran 50 rounds of Remington's .223rem, and another 150 rounds of Norinco's...everything is a-ok !
The action did indeed stayed open after the last round was fired, and I must say the SU16-FX is a dandy little devil of a... .223 rifle !
Had a Nikon scope mounted, and it was "ringing" the gong off at 200m...
The disassembly of the FX is somewhat different from the regular SU-16s ?? But the instruction booklet that came with the FX is of the regular "kind !"
...I'll probably cycle through another 100 rounds before cleaning the bolt carrier,etc ...maybe I will just find out for myself if the Norinco's are really that... "dirty!!"