Upgrades for my G&G M4
 

Hey guys, I have a G&G M4 pneumatic blowback. I'm looking to ugrade my spring, (I'm not sure what it is I have that I'm going to put in, but it's most likely an M120) so to do that I have to also upgrade my internals. What my friend told me I need is the following;

New piston and piston head (he said piston would be better with metal teeth)
New metal cylinder head
Metal Hop-up
and new gears.

Can anyone direct me to the right parts to order? I don't have a huge budget, and I'd prefer if they were from airsoftparts.ca or airsoftdepot.ca.
Thanks!

If it's currently all stock parts, just upgrade the piston head for a polycarbonate one (not metal) with bearings, and a metal bearing spring guide. You shouldn't need new gears for an M120 spring. A metal hop up chamber would be good if only your current one has problem or you'll just be wasting money for no reason. You can get everything I've listed from airsoftparts.ca. Cheers

P.S. also regarding the piston, use it until it's stripped or worn out. You really don't need a full metal rack of teeths because you want the piston to wear out and not the gears.

The strength of G&G gears are some of the worst I've seen. Putting in a spring that shoot much more than 400 FPS will consistently strip the teeth on the spur and sector gears. The teeth on the stock plastic piston and bevel gear don't seem to get affected for some reason. So yeah, keep that stock piston. :)

I have seen that happen a lot with G&G gears. But an M120 ain't a very heavy spring so it shouldn't break easily if shimmed correctly and AOE. I still believe that the stock gears should be fine with an M120 but if OP is concern, upgrade.

I just built a G&G m4 for a buddy of mine this last summer, list is as follows:
-ARS Gen 2 bearing piston head
-ARS Gen 3 V2 cylinder head
-Guarder sp110 spring
-Modify type 2 port cylinder (363mm barrel).
other than a very good shim job and new lubricants everything else was bone stock. Through the chrono it was shooting very very consistant 400 fps....very consistant :D.
Spend time shimming the gears so there is no play and you will be surprised how much abuse they can withstand.

My friend said that my stock gears should be due for replacement by now. I'll have had this rifle for a year around May. My other friend has the G&G M16 (the basic one I believe) and after about a year of having it, one day during a match his gears wrecked...So just to save me the inconvenience of that happening, I'm gonna replace them.
If I'm correct, the spring I have is supposed to increase my FPS to around 420-450, not sure if that's an M120...

And does anyone know if the MASK piston heads are any good?

with a good air seal and standard M4A1 barrel length, you should get 400 fps (-/+ 10 fps) with a M120 spring. CQB barrel length will get you 370 fps (-/+ 10 fps).

Modify Parts are cheap and high quality and you can order them from airsoftparts.ca.

I have my G&G M4 fully internally upgraded except the gears for $100CAN abouts.

One problem with alot of the G&G's I have noticed and seen has been the o ring on the piston head. try just putting a new o ring on it and test compression.

Also depends on what G&G you have as some come with a bearing spring guide and or piston head with bearings

It's not just the O-ring, it's the piston head design aswell... it's EXTREMELY poorly designed. After a few thousand rounds it's very common for them to crack.

I have a g&g m4 cqd and I am actually impressed with the internals on it. I've run many thousand rounds through it and all I had break was a piston head. Replaced that with a poly one from airsoft parts and was back up and running. With the stock spring and all stock internals (less new piston head) with .20's it shoots a little over 400. Has bearing spring guide and bearing piston head spring guide too. Ball bearings on all the gears shafts too. I'm gonna keep it as is until things break but so far so good.

+1 to cetane

I am rocking the G&G M4-CQB/R, and only upgrade I have done so far is to put a longer tightbore/silencer combo on it. I am using the "Stiff Dick" theory with mine...if it works, don't mess with it! :)

On friday I'm opening my gearbox for an inspection to see what I need most at the moment. I'll keep you posted on what the situation is in my gearbox, after that we'll conclude what I really need.

+1, G&G piston heads suck, prone to cracking/shattering.