[MultipleParadox]

Hey guys, I need some help on that one. Here's a little story:

Got a King Arms M4. Was completely stock and working fine except for the compression that was crap and getting worse and worse.

I put a prommy 6.03mm. Use my original bucking that seemed a bit weathered but not too bad.

At my last game, compression issue was now unacceptable, as it chronied at about 260-270fps. Still gameable but like crap. During the game my Aeg started having feeding issues. I immediately thought about the bucking needing replacement.

Then I order a new piston, piston head (mask), cylinder head (mask), bearing spring guide, o-ring'd nozzle, shim set, madbull shark bucking and fishbone nub, and an Ascu2. All this should solve all my issues right?

Start replacing my stuff, try to shim my gears, without success. So I give all this to a gun doc who proceed to do it for me; check up my gears and turns out the spur gear is apparently crooked a little and need replacement. Full gear set is ordered and installed, shimmed, and all parts listed are installed.

I test the thin quickly after all that is done: seems to work fine for a few shot, put the aeg back in its case. (the original bucking/nub was still installed)

The day after I give it a try, and it doesn't feed correctly:
The first few shots get stuck in the flash hider (exited the inner but not the outer: wtf?). I clear that up and try again. Some get stuck in the inner, some get out, 2-3 at a time, like a tri-shot shotgun :/

Change the nub and bucking. Very hard to install as its much thicker than the original one. Try again, same thing. All this with hopup at 0. Turning the hopup would make the BB curve to the left a lot. But that's probably the nub not being seated correclty.

Change my inner back to the original one (6.08mm I think), same issues again...

I'm really not sure what to do about this... Anyone has some kind of idea or something?

Thanks for your help

MP