AOSC Forum Archive

I'm just wondering if a Systema Complete M150 Gearbox for M16 models would fit in M4 models..

It should they are both the same gearbox.

The short answer is yes, a Systema M16 Drop-In will "fit" in a Systema compatible M4 gun. However, the difference between the M4 and M16 Drop In Gearbox is that the M4 gearbox is wired to the front, while the M16 gearbox is wired to the back.

P.S. I assume you are wanting this gearbox for your G&G M4. I hate to be the bearer of bad news but, G&G is not compatible with the Systema Drop-Ins without significant modification to your lower receiver. G&G's use a different type of Selector plate and trigger group. My suggestion to you would be to buy a tune-up kit instead of the entire gearbox, and just change out the internals of the G&G gearbox.

P.P.S. What is with everyone all of a sudden wanting a Systema Drop-In?

Sorry, that was probably my doing lol. Lots of people wanted DMRs, and I told them the best way to do it .

As usual, Adrian has great advice. The only thing I want to add is that you should also buy a reinforced shell if you are putting in an M150, as your stock shell may crack.

<----- Didn't buy a Systema.  I saved my self a lot of dough and went with a Matrix one.

I guess I'll pretty much have to flush out the internals.
Another long term project. Greeaat......


Thanks for the help, though, folks!