So a friend of mine gave me his PSA "Dissy" style upper that he purchased against my advice. It doesnt run.
So initially I thought it might have an out of spec chamber that was causing 5.56 casings to stick as the owner told me that it runs better (but far from perfect) with .223 cased ammo. I used one of Ned's chamber gauges which confirmed that the chamber was indeed tight. I ran one of Ned's ingenious reamers thru it and it definately removed some material from the chamber
After running a few mags of different ammo through it today to see what was up, it was still suffering from some odd (to me) double feed/failure to eject/Im not sure malfunctions. So the out of spec chamber obviously is not the only issue with this thing.
I tried to take a video of the cycling but I picked the wrong resolution on my phone so it is a bit grainyhttp://www.youtube.com/watch?v=cgAGrmp_SIc
Heres a couple of pics of the stoppage:
Please, no comments the Zombie theme crap
Anyway, it appears that the fired casing is being held by the extractor claw all the way to the back of the ejection port and being ripped away by impacting the rearmost area of the port. Not positive about this but every casing fired from it has the same score mark mid casing. Most of the casing that actually eject are going almost straight forward after striking the back of the ejection port.
Any help is greatly appreciated as at this point all I can confirm is that this PSA upper is a bonifide P.O.S.![]()





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