Start by stripping the sling off your combat machine.
Put that sling on a new G&P
Throw away the CM.
NA, but really.... ask yourself what you want. A nice eye turning rifle, or a $100 rifle with a lot of time and money into it...
I have found that often, after getting everything you want in the gun, it would have been far cheaper to just buy a higher end rifle, and replace one/no parts
The combat machines are good $100 dollar guns. I just dont recommend messing with them unless you have too, IE something breaks.
A huge step here is, can you take apart gearboxes/work on guns? Because if you cant, its either up to you to learn, or your going to have to go pay an expert to fix it for you. In which case, its going to get a tad more pricey, and the new rifle shipped to your door starts to look real good.
Because, for the sake of everything you love, if you don't have a clue about shimming, aoe, compression tips ect. your "upgrades" may very well end up wrecking the rifle.
IF you are certain you still want to/think you are able to complete the upgrade. GO for it.
Since you have an M4, you can put a new tightbore barrel and motor in the gun without opening the box up. A CM with a tightbore should be more than adaquate to get some hits.
If you have perfect compression, and are getting all your possible air, but still want more FPS (Really not better from a point)
your going to have to put a new spring in there.
AA Standard,
Get an M120
Get an SHS/G&P 120 motor
Get a tightbore
Upgrade your battery
You want to go all out.
SHS motor
SHS 13:1 Gears
SHS metal tooth piston
Mosfet
11.1 Lipo
Tightbore
hop mods
compression mods
ect.
