Of course I immediately dumped about 200 rds through the RFB. Once I had the gas settings on...flawless. Topped it off with a Vortex 3x optic sight, it just don't get any better than this. Very low recoil, takes the metric FN mags,right or left hand use, very well built. As for the KSG, well 2 tube mags which hold 7-2 3/4" shells each...do I have to say more?....