I've been involved in airsoft for a few years now, and am just now deciding to do some internal upgrades. I got my 2009 JG M4 s system enhanced version a few months ago, and it performs like crap. I sent it back to Airsoft Megastore, they replaced the bucking, and sent it back claiming it was fixed. Well it wasn't and I really didn't want to spend another $50 to ship it back and have them not fix it. So there. There's my reasoning for finally getting involved in upgrades. Sorry for the rambling. I'm looking to get about 20rps while using an M120 spring, my question is, what do I need to get to achieve that goal, and keep my gun from breaking because of it? So far what I'm thinking is: Shs x-mod soft hop up bucking Src 2 piece hop up chamber Shs x-mod metal air nozzle (has an o-ring) Shs x-mod metal cylinder head (with double o-ring) Shs x-mod 16:1 low noise gear set Shs x-mod metal spring guide (bearing) Aps polycarb max compression piston head (not bearing) Shs x-mod shim set Shs x-mod 6mm metal bushings (not bearings) Intellect 8.4v mini (would get a 9.6, but the battery comp is tiny) And then leave the piston, cylinder, spring, trigger stuff, and motor stock. Suggestions? And I'm planning on just going to a hardware store and getting some superlube. Other than that, I would perfer to get everything from the same place online, and call me stupid, but all the stuff listed is from Airsoft Megastore, I have bought from them in the past and had good experiences.