I have recently installed a TN M16 6.04mm inner barrel (509mm) and a Systema M16 Cylinder.
When shooting, sometimes bb's come out, sometimes they don't. When they do, 2-3 come out at once. On occasion, one comes out at a very slow velocity, almost rolling out the barrel speed.
I'm thinking it could be suck back, as I have compared the air being expelled out of the barrel to my friend's stock m4a1 and both are exactly the same.
Could there also being anything in the gearbox that may have been affected during the cylinder install that would cause this issue?
Thanks,
~David
