Originally Posted by DarkAura
Was this version 1 or version 2? Version two has a V3 gearbox with metal gears. I'm going to take a stab in the dark and assume it was version one that had the polycarb gears, right?
Both are exactly the same, kinda
V2 has "enhanced" internals, but APS being APS, they suck. V1 had a poly piston and shody (metal) gears. V2 has a decent nylon piston and "better" gears, though they are sub-par with everything on the market. If you need replacement parts, the gun takes regular AK V3 everything aside from the right-side transfer plate.
Nozzle is a standard AK and hop-up is a copy of the ProWin AK. You can actually install a ProWin in case you need to replace it.
Outerbarrel is a M4-CQB 10" barrel. Any other M4 barrel will fit IF they are slim near the rear. Real barrels are not made like that but AEG's usually are slim under the handguard to fit batteries. In the APS UAR, the trigger and fire selector control rods take that space.
Battery space is not that bad. It fits any "mini" pack or LiPo that fit in the same space. Really easy to install too, there is a trap door at the front just over the barrel.
The gun is a PAIN to take apart however. I had to cut the barrel to be able to open one (the fire selector control rod was undone from factory).
Best "option" is to turn the plastic nut around the barrel 1/4 turn and pull is forward. Then follow the rest of the instructions from the manual.
The "modification" you have to do is cut the plastic in the mag well to clear the "bump" on top of M4 mags. The cutout is too small and the section that houses the latch/retainer on M4 mags does not fit. As other said, 2 minutes mod.