I love that IAR, had I not bought an M4 I'd make one for airsoft..... Really it would just give me an excuse to carry 20 mags lol
My advice is to stick with lowcaps, just carry more of them and hold down the trigger longer, works for me lol
Okay so basic internal upgrades assuming your M4 is TM or CA:
metal bushings
shims
Systema poly piston (NOT area 1000)
Systema silent head set for V2 gearbox
If its a CA, keep the stock spring, if it's a TM you could use an MS100 (around 340fps).
High speed gears will increase ROF, so will upgrading to a larger battery (either going from mini to large, or 8.4v to 9.6v). Personally I don't like raising the ROF past 1000rpm but you can do whatever you like
