Retro Arms CNC SOPMOD M4 NGRS Gearbox 8mm pre build 5 joules we needed proper

5 joules we needed proper air volume installed a Real Deal 75% steel cylinder

Build Specs ect

Bottom of page will contain gearboxes tested

This upper has picatinny rail space on the lower portion to be able to mount grips and hand stops

Retro Arms CNC SOPMOD M4 NGRS Gearbox 8mm pre build 5 joules we needed properRetro Arms CNC gearbox for TM NGRS SOPMOD M4 AEG. When it comes to building a reliable high tier NGRS, this gearbox should be your first item in your build. With the stress of recoil, you need to have the strongest gearbox possible. Precision machined from a block of billet EN AW 7075 T651 aluminum Durable anodized finish Reinforcement in key stress points to counter rapid wear from high performance parts Pre radiused cylinder windows helps evenly