Technical information

Practical A.E.G Upgrade 2006

Version 2 mechbox versus Version 3 mechbox: any difference in stock

performance?

TM metal mechbox versus Cybergun plastic mechbox?

We have heard people saying that due to a better design, guns running on the

Version 3 mechbox (such as the AK and the SIG) can offer better FPS by default.

Frankly, this is quite untrue. Both mechboxes share the same internals (gears,

piston, cylinder and spring), therefore it is not likely that one can outperform the

other without modifications. The true reason why V3 guns offer better stock

performance is that these guns are based on better overall gun design so that air

leakage is kept to the minimum. TM AK is an obvious example – sometimes it

can shoot at a FPS well over 300 under purely stock configuration.

Most V3 mechboxes do come with more reliable select fire mechanisms (such as

those gear based mechanisms in use by the AK and the G36). Also, because

some V3 mechboxes include a motor mounting frame for mounting the motor,

mechbox testing can be done almost on the fly without the need to first

assemble the lower receiver part of the gun.

We have heard people saying that the Cybergun’s DPMS AR15 is crappy due to

the use of plastic internals. These people obviously have no clue on what they

are talking about. All ACX and Cybergun’ AEGs are based on the metallic Version

2 mechbox. The primary difference is that the ACX/Cybergun mechbox has an

EG-560 compatible motor affixed by two screws. Its’ diecast is also less solid

when being compared with a TM, but based on our test result it can still survive

a M120 (with NO spacer on either end of the spring) + 9.6V combo.

Plastic mechboxes do not have to be bad. In fact, some recently marketed

made-in-China AEGs (such as the BE Tech AUG/XM8) can shoot at around 330

FPS perfectly fine using plastic mechbox and gears.