||quality gear box
workmanship is up there with the best ive seen.
shimmed really smooth.
installed into matrix m4 with 363mm 6.04 brass barrel
blowback plate not used, removed blowback spring from top of gear box
very nice fit.
swapped out oem spring for matrix m130
running 11.1v 1300MHA 15C BATTERY with matrix high torque motor.
puts .23gr bb through one side of 5 gallon bucket at 50ft, sometimes both side.
its such a quality gear box that i purchased the APS ASR 110 m4 today as it also has a hybrid gear box only difference is 7mm bearings instead of 8mm.
Rating: [5 of 5 Stars!]