"This gun is a good gun, but the blowback ruins it. When i first opened this gun i started shooting it, 20 rounds later it stopped firing. I took the battery out and messed with a couple of things then started to shoot it again, but this time putting only 10 rounds into before it stopped. I took it back to the store and the guy there test fired it, the problem happened again. He then tried to give me another one. I insisted it be test fired in their back range. As we fired it, the same problem occurred. The guy told me it had to be something with the blowback. I then got my money back in store credit and bought the Colt M4 CQB by CYMA. This gun is a lot better, heavier, and better quality. If you are looking for a good M4 A.E.G, look no further then this gun. Click this link to go to the gun- ( http://www.airsoftmegastore.com/453_FPS_COLT_M4_CQB_R_Full_Metal_AEG_Rifle_p/cb-18975.htm )"