Pictures will be posted within the next 24 hours as well as an update on th air leak factor.
• I have identified the air leak sources after swapping out parts one at a time. The piston head is 90% of the airleak and the air-nozzle completes the leak. Swapping both of these parts out results in a very tight air seal. Also the cylinder is incorrectly ported. Picks up tomorrow I have been busy. I have found the reason the selector switches came loose. I over torques them so the issue no longer applies.
Cyma has long had a bad reputation for cheap low quality airsoft guns. With their new lineup of aegs they have clearly made the right steps to change this assumption.
At first glance the outer metal body looks pristine. The metal buffer tube and front set mesh well together when coupled with the butt stock. The cyma 556 sports a sleek rear flip up sight which is PERFECTLY line up with the front sight. That last comment needs to be fully explained to be appreciated. While looking down the pin whole of the rear sight the only object visible to your eyes focus is the circular front sight. A well crafted outer barrel feels solid along with the 14mm ccw flash hinder. There is no wobble present at all. The lines of the gun can only be described as godly when you take a close look at the meeting section of the upper and lower receiver.
I must say the texture of the metal body is extremely satisfying and the pistol grip is built like a rock. The magwell holds the stock hicaps with ease and they feed surprising well. I actually jumped on one of the high cap mags to see if it would break (I planned on buying mid caps anyways) and I was stunned to see no damage at all caused by my 180lbs body. The only complaint, exterior wise, is that the ambidextrous selector swith is very loose on the right side. It can't be fixed on my aeg anyways as it seems to bE a defect upon closer inspection. On a side note I find it hard yo reach the mag release as it's positioned too far forward and you actually have to put the gun down to reach it in my case ( I am 5'11)
Now onto the internals. The cyma 556 sports a classically crappy stock battery, motor and charger. While as a massive bonus the wiring, switch assembly and motor mounts are far better than what I've sen from cyma in the past. The custom (yes custom - don't plan on replacing this mechbox anytime soon) is rock solid with an amazing feel to it. The custom selector plate is also really nice and moves extremely easily. The gears have been a complete shock to me. I would have to say unless you plan on moving yo high speed or high torque applications keep them! They appear to be perfectly machined and I put them into another aeg that rubs at 30 rounds per second at 385 fps and they held up well. The upper mechbox is where the standard cyma rep kicks in. Plastic spring guide, plastic piston (all ready showing wear after only 400), terribly poor piston head and cylinder head. It also seems that cyma designed a new air nozzle specifically for the 556. All three previous sig 55x nozzle don't match along with a standard m4. The bad news here folks is the cylinder, cylinder head and piston head all air leak badly. The tappet plate is way to flexible as well. I almost forgot, the mechbox has very well crafted screws and tight threading and sports 7mm metal oil channeled bushings.
Now to clear things up the hop-up is basically a sig series hopup in cased in a box which redirects the bbs to allow standard m4 mag compatibility. The hop-up rubber is very good as well as the nub. Is tempered enough to handle 400fps plus. A major flaw in the manufacturing will cause some headchs though (confirmed this issue on Google). The inner barrel is 363mm and it's straight on the outside but the inside is a mess. Plan on having bbs flying a little to the left. Truth be told I don't know a single player who hasn't moved to something along the lines of a 6.03mm barrel anyways.
Summary: (buy this gun for the external qualities alone)
internals 5/10 (amazing gearbox shell,hop-up, gears and 7mm metal bushings)
recommended upgrades & changes:
battery, charger, motor, cylinder, piston, piston head, cylinder head, spring guide & tappet plate.