AEG making noise, but not firing.
 

Hello, so a few days ago I bought a CYMA AK-47 CM.042A. At first I used the BBs that were in the package with the gun. They worked good. Automatic and semi-auto. But that same day I tried 0.25g BBs, but they didn't work. They were getting stuck in the barrel. Then I tried 0.20g BBs and the same thing happened. The brand is shootONE or something like that. It's not a problem with the battery or the magazine. The BBs are just getting stuck in the barrel...
(Sorry for my english, im not a native english speaker)

First thing I'd check is to see if there isn't a piece of broken BB in the barrel. Look for an obstruction in the barrel. Also make sure the hop up isn't adjusted all the way up. In fact, slide the hop up adjust lever all the way off. This will give a 'straight through' path for the BB, or should. If the BB's are still jamming, it could be a problem with the BB's. If you've checked the barrel, and adjusted the hop off and they're still getting stuck, try a different brand of BB. It sounds like the BB's that came with it worked fine, and the others didn't, I would suspect the BB's.

Thanks for the advice. So I checked the barrel and there weren't any broken pieces of BBs and I already tried firing with hop up turned off. Still didn't work. I'll try using a different brand of BBs. Are there any that you would recommend for me?

Turn the gun upside down and see if it shoots. If not, try to see if your nozzle is engaging the bb's.

Remove the magazine. Use an unjamming rod to make sure the barrel is empty. Turn the gun upside down and look into where the bb's go into the hole and pull the trigger. Do you see a piece of plastic moving in and out of the hole?

Tried turning it upside down. Didn't shoot and yes the nozzle is engaging the BBs. I can even feel the air coming out of the barrel when shooting without magazine.

At this point I'd try any other brand to see if it makes a difference. Not sure where you are, but where we are we've got Green Devil, Valken, Golden Ball, and even the new premium C-Tac BB's work great. I know, haters gonna hate, but those new C-Tac BB's are actually really good. Then again, the tightest barrel I run is a 6.03...so nice and loose.

Hi. Sorry for the late response, but i did not have time. So I bought some new BBs (Madbull, 0.2g). This time it fires 5-7 BBs and then nothing and occassionaly one or two BBs. (And sometimes some just fall out of the barrel) They are getting stuck in the barrel again. Once I cleared the barrel with the unjamming rod and 3-4 bbs fell out. The shootONE BBs didn't fire at all... soooo...

Well, it sounds like you're improving...slightly. Madbull's are better. Ok, so next thing to check if the barrel and feed path are clear, is the magazine. Check and see how the magazine aligns to the feed tube at the bottom of the hop up. Misfeeds are a problem on some AK's. On my G&G for example, the BB's were getting stuck on the edge of the feed tube where it went into the mag. I modified the feed tube as well as a few other things and it runs like a boss.

If you haven't done so yet, try lubricating the magazine lightly with silicone spray...

You lost compression in your gearbox. The BBS should not be piling up in your barrel like that. This means that your compression is failing and the piston is failing to push air into the barrel.

The bb's that shot once are twice is probably a fluke from the o-ring getting dry and catching something.

Even though you feel air coming out of the barrel it might not be consistent. With an empty magazine inserted, shoot 10-20 rounds in front of a free floating piece of tissue paper. The tissue should move radically and get pushed back.

If that is not the case, weve isolate the problem to the barrel and the hop up unit. Give it a good cleaning and try again if you can.

The improvement from changing BBS is negligible since the same thing happened after the first 3 shots.