JG M4A1 GBBR

Here's the review on the JG M4A1 GBBR by KWP, on Arnies:

(http://www.everything-airsoft.com)

1. The Jing Gong M4 GBB rifle is another replica of the WA design.
Just like the AGM M4 GBB it's targeting the bottom segment of the market.
It's even a little more affordable than the AGM (e.g. at this date an undisclosed shop sells the JG for US$85 and the comparable 061 model from AGM for US$110, both plus shipping).

2. First thing you notice is how much lighter the gun is compared to the AGM. Not only the gun itself because of the plastic body, but the 300g less weighing magazines are a tremendous difference (JG: 500g, AGM: 800g). The magazines from the outside are pretty much the same design, just the finish is a lighter gray. It also has the bolt stop selector switch allowing you to activate/deactivate the bolt stop function. The mags were a tight fit in the mag well, but were no problem to insert or take out. Pushing the mag release didn't make the mag fall by itself. Just wished there is more positive and noticable feedback when the mag has clicked into position. But no mag swelling or other problems. The BB spring is stronger which should benefit the bolt stop function (Bolt stop worked 100%). Filled with Green gas no leaking was noticed. If there is, it must be insignificant. At least I couldn't hear any hiss, nor did I experience any excessive performance inconsistencies while firing the gun or chronoing.

3. The body is of reinforced plastic and makes a sturdy impression. The trademarks are a different story. Well, the trademarks themselves aren't that bad, but they are framed by a thin line that got onto it during the stamping process, I guess. That gives it all real cheap look.

4. What about the metal parts? Pretty much the same as on the AGM. What should be metal is metal except for the receiver body and the buffer (which is also plastic in the AGM). The magnet test showed quite everything must be some kind of alloy, but to my surprise the magnet was attracted by two parts: the flash hider and the lower part of the carrying handle. The fire selector sits much tighter inside the receiver and needs some force to turn it, but clicks nicely into the positions and best of all is that you cannot accidentally push it out like on the AGM, it's a real tight fit. As expected all the internal mechanical parts are not steel. The bolt is made of black plastic fitted with a copper nozzle. I couldn't check the hopup yet, but looking down the barrel I could see the rubber protuding inside of it and it seemed to stay in that position. Turning the dial though didn't seem to show too much effect. But that needs to be tested more thoroughly.

5. Worth mentioning is the bolt carrier does not have that tiny steel piece to reinforce the part of the bolt carrier that slams against the bolt stop. The bolt stop itself though has that steel piece, just like on the AGM, and is now spring loaded. Along with the strong magazine spring this seems to have ironed out the bolt stop malfunction some AGM users experienced. At least during my testing it always engaged after the last round shot or when thingying the gun on an empty mag.

6. There's not much to say about the lower receiver parts at this point as this would require an endurance test to see if, how and when something breaks. But so far they look the same as in the AGM except for the bolt stop that is spring loaded now.
The recoil buffer is a black plastic piece and the recoil spring metal (and if it matters a shiny piece of metal resembling the looks of stainless steel which it certainly isn't).

Edit: Yes, it has a realistic looking metal gas tube going all the way from the gas block into the receiver body. The handguard is of decent plastic and there's no hassle with the delta ring to remove or put them back together properly. The stock was pretty wobbly.

Link: http://www.arniesairsoft.co.uk/forums/index.php?showtopic=172628&st=0&p=2157413&