Cannon Flannel details his M4A1 URGI MK16 GBBR build in this episode... "In this video, I break down my CGS M4A1 URGI MK16 GBBR build piece by piece. From the replica itself to all the attachments, I’ll show you exactly what went into this setup. Perfect for anyone interested in airsoft GBBR builds, URGI replicas, or looking for inspiration for their own rifle."