||The King Arms M4 GBB is my first GBBR, I had some experienced with gas guns from my Tokyo Marui Glock 18C. GBBs are so much more realistic than AEGs with the kick (AEGs are boring). I have installed Daniel Defense Omega X 7" and real steel ACE stock. I recommend switch to WA/G&P system, get new bolt and mags.
500 FPS ~ 300 FPS (adjustable)
ROF is adjustable
Compatible with real steel parts (externals only)
I accidently stripped the threads (14mm +) on mine
I've had 3 Magazines, all leaks and reject gas
Rating: [4 of 5 Stars!]