"The gun works very well, but the flash hider is extremely difficult to twist and I haven't been able to take it off completely, I would like to know how to take it completely off.
"Quick conclusion: After owning well over 20 different airsoft guns and teching for a while, this is one of the only new airsoft guns that I didnt really find any major flaws in out of the box - except for that the battery space is a bit narrow (but long at least) .
Gearbox: I dissassembled the gun on the first day I got it to inspect the internals. I was surprised to see a type 0 cylinder (no ports or holes) for the given barrel length. Typically those cylinders are used for longer barrels, but it should be fine, not that big of a deal. I used it for my rpk. The aoe was not correct, but its almost never correct out of the box for any new gun, so no worries, just cut the second tooth on the piston and add a sorbo or something to move the piston back. Gears were fine, compression was ok, has a metal bearing spring guide if I remember correctly. Metal bushings. Not a bad gearbox! Selector gear was plastic, so dont go ham on the selector switch.
Externals: Amazing! VFC style using pins. Mostly made of steel (checked with magnet), and plastic furniture feels like good quality. Stock is sturdy, hopup chamber is metal. Charging handle does sometimes catch on to the hopup adjustment, but I just grind down the hopup tab a bit so it doesnt touch it. Weight is perfect. Mag is plastic and lighter than my other 5.45 style mags (for ak74), but feeds actually quite well.
Try heavy bbs, it likes them better (at least .25s will do). Dont use .20s, they tend to either be overhopped or underhopped. Be cautious of the battery space, its long but narrow, barely fit my 7.4v lipo battery. Believe me, after changing my loadout a buch of times, out of all guns ive owned, the ak platform is the most practical - mags hold a ton of ammo, strong body that is durable, cheap compared to m4s, v3 gearbox which is more durable, and feels like a real gun in your hands. But buy whatever platform you like, the ak is just my favorite so far.Awesome rifle, definitely keeping it as a lender gun for friends!