I looked carefully along my rail and discovered that the tip of my outer barrel was looking visibly to the left, past the front sight post. The G&G outer barrel is made of two segments connected right behind the front sight. The inner segment is straight but the outer segment has been set during assembly at an angle that shifted the front sight very little, but the muzzle a lot to the left. Luckily not enough to bend the inner barrel. At the connection point there are two small screws. It only took to remove one and the barrel snapped back into place. The whole contraption is also supported by the ring under the railed handguard, so the gun is shootable but not solid. The front outer barrel doesn't move or anything but sure doesn't inspire any confidence. The gun actually shoots pretty good now, so for making holes in paper I am satisfied. Other than that, I am looking at getting a new outer barrel soon.
For those who own a G&G Armament CM16 Raider-L, I am ready to help with more detailed description, for those who don't, my advice is to look elsewhere. G&G has obviously sloppy quality control; pay more if you have to, but buy something else. As for me, I like to fiddle with my things but fixing ineptitude in manufacturing is no fun. I also feel like a fool for not having caught it when I bought the gun.
Thanks a lot to all for help!
Shoot happy and straight (now I do too).