A good support gunner's gearbox.

I decided to go with a support gunner for my M4 for the team since we don't have any support gunners.
I was wondering what would fit well for the role for a gearbox?
Since I'm going to be spraying would a polycarb piston be good?
Do I also need better bushings, and I high-torq motor?
What are the absolute NECESSAITYS that a support gunner might want to have in his gearbox?

you want something durable because yyou will be pumpin out a lot of rounds.

So a polycarb piston would that work?

Wait, how the "Watch your language" are you going to mod a M4 to take a different kind of mechbox.

No for a high ROF set up you do not need to change out the mechbox...(which is almost a impossible mod, you see mechboxes are designed to fit the guns specified for them).

First I would buy bearings, these are kind of like bushings, but if you skate you would be familiar with them. Only these are on a much smaller scale. (6mm diameter) Then I would do a AoE on the piston. I would invest in a high speed ratio gear set (anywhere from the cheapest bing $13 to $50+), a super torque set would do the exact opposite of what you want to acheive. DONE

Second, Just note.. I know you may think you need to change out the spring, only case is to get a weaker spring, however a stock spring is absolutely fine for a SAW.

Third, Electrical, once you have it set up right, you could possibly put a lipo in the gun for a lot of ROF, however these batteries are naturally very hard to maintain properly. SO I for my cheap self, I would just get a higher voltage NiMh (9.6 to mayve a 10.8v). Another area you could upgrade is the wiring itself, but that is a little harder than just upping the battery, but your results may bring your RPS up to maybe 3-5+ your current. If you do replace wiring, use 16 - 18 AWG "wet noodle" which goes for about $8 per foot. And trash the tamiya connectors, go with deans or if you want, the cheap route is soldering the wires together in a joint. not recommended if you want "ease of upgrading" As for a motor, you want something meant for highspeed, but it is not absolutely necessary if you are satisfied. Motors TM EG1000, Matrix magnum highspeed, and systema...

Other than that, good luck and i'll be happy to clarify any of this if need be.

Lonewolf you got a diffrent message.
I pretty much meant, what would be a good way to upgrade it...
New Piston, Piston Head, Spring, bearings.
But I'm a low budget, so I'm looking for the nececassitys

Okay, start with the AoE adjustment, and put in bearings.

What is an AoE adjustment?
Sorry I have no idea what that is.

No problem thats why I don't mind clarifying.
AoE - Angle of Engagement

The basic idea is getting the sector gear teeth to mesh completely on the first tooth with the piston, which is done by shimming the piston head to fill in that space. But not with the shims you would uses on your gears. Anything like plastic washers. Which you install by removing the piston head, slide washers onto the screw which should be sticking out the back of the removed piston head, then screwing it back in.

Here is a guide I found on it a little while ago, http://www.airsoftretreat.com/forums/index.php?PHPSESSID=2d7abd2d6235084a5b9700598c6c9e6c&topic=77728.0

Its not much, but it makes for reliability to any upgrades your going to be doing. If you buy a new piston, you don't need to readjust it if you kept the same piston head, but if its off, go ahead and redo it.