Description

In the words of RetroArms
CNC gearbox designed for M249 or PKM airsoft replicas. This gearbox is manufactured from one solid block of aircraft aluminum (Dural) EN AW 7075 T651, which has higher strength (590MPa), than common construction steel (390MPa). Because of used material, our gearboxes have the best durability and resilience than common zinc-aluminum gearboxes. We are manufacturing these gearboxes on our precise CNC milling machines in our factory. Detail in bracket (8mm) means diameter for bushings/bearings.
Both halves fit together with absolute precision including bearing holes, which are 100procent co-axial.
It’s made with slots for 8mm bearings. Bearings and spring guide are not included. You can choose them from our offer here. 
Gearbox is equipped with quick spring change system – QSC. Standard spring guide can be used, or you can choose our CNC one.
Gearbox can be equipped with standard Hop Up Chamber, or you can use our CNC one. Retro ARMS CNC Hop Up Chamber can be attached to gearbox by two screws. It will ensure that it will stay in proper place during firing compared to standard one. More information about our Hop Up Chamber can be found here.
Further small features:

accurate hole for Anti-Reversal Latch – it doesn’t fall out
micro grooves on pin, which holds tappet plate spring – springs doesn’t jump out
new laser labels with unique serial number

Package includes 1 x gearbox for M249/M60, strength screws and Retro ARMS sticker.
Gearbox comes with lifetime guarantee against cracking. It doesn’t relate to breaking caused by misused parts, e.g. improper cylinder head.
We try to adjust our gearboxes as much as possible to allow use of the widest variety of part brands. However we still recommend to use Retro ARMS spare parts, because they are the most compatible. We can’t guarantee 100procent compatibility with spare parts from others.
We offer many more parts for this gearbox. For example thrust nut for spring guide, capture for spring guide,…
Gearbox installation requires technical knowl..