Prometheus EG Barrel Wide Mechbox Pro This HK 416 will send

This HK 416 will send BBs downrange at 420 FPS

Detail in bracket (8mm) means diameter for bushings/bearings

The ATPRO design is based on the latest generation of Maxx hopups (M4A/M4P)

The KM4 Series tappet plate is made from high strength polymer and will fit all 2GX mechboxes

20 gram BBs to launch at 300 FPS

Prometheus EG Barrel Wide Mechbox Pro This HK 416 will sendInner diameter 6. 030. 01mm with dimensional tolerance! Wide Expanded HOP window for a variety of HOP nubs and tensioners Introducing Prometheus EG Barrel W; Wide Expanded HOP window model, based on our EG barrel with the renewed Wide Expanded HOP window for a variety of HOP nubs and tensioners. Inner barrel bore width of 6. 03mm with a tolerance of 0. 01mm, made of stainless steel (SUS) for superior strength necessary to maintain accuracy without the