To be honest, probably a new hop up rubber and nub, The hop up rubbers that come with most clone AEG's suck. Your's is no exception. I would replace the hop up rubber ASAP before you start messing with anything else. The cylinder volume is fine, I promise. You are not going to see problems with barrel volume untill you get to much longer barrels (like an M16 length tightbore on an M4 cylinder)
I agree entirely. Especially when going from a stock e1 barrel to a 6.03, I've noticed a lot of buckings don't seal when placed on a madbull barrel, also. It could just be me, but I can't get a systema bucking to seal onto a madbull or prometheus barrel for the life of me. But that's me, systema buckings are supposedly some of the best. Don't let me talk you out of them. lol.
Also, your 9.4v battery? uh... what kind of battery is that? Maybe a 9.6 or an 8.4?
Maybe try taking the tracer unit off (If it's aligned improperly, the bb's could be hitting it).
What part of the performance sucks? What is the gun doing, and what would you like it to do? What's your budget?
For example:
Problem: My shots go flying everywhere and my hopup isn't adjusting to be right where it should be. I would like my shots to be more accurate.
Solution: Replace your hopup bucking and nub, we'll go from there. (It will cost you 5-15 dollars, depending on what kind you get)
Problem: My fps is super low, and I would like it to be in the 400 range.
Solution: Replace your spring with an sp110 or m120, bushings with metal bushings or bearings, spring guide, and piston with a polycarb, and your nozzle with an airseal nozzle. Also make sure you have already replaced your hopup bucking, barrel, and nub.
Problem: My rate of fire isn't as high as I would like it, I use a 9.6v 2200mAh mini battery.
Solution: Switch to a higher mah battery, a 10.8v battery, or a large type battery, or a 11.1lipo if your internals are beefed up, or a 7.4 lipo with a high c rate and high mAh rating, put in a softer spring, switch to high speed gears, switch to a low-resistance wireset, add a mosfet, put in a high-speed motor, switch to dean's connectors, get a low-resistance fuse, or all of the above. lol. RoF has bajillions of different ways to increase.
And to answer your other question. No, not all parts are 100% compatible. For example: If you're going to switch out a cylinder, get a cylinder head and piston head that are known to work well (same brand usually works well, although I've seen JBU have 'matched sets' that are so far off it makes people cry). However, for switching inner barrels, they're all compatible, but most stock buckings and nubs suck. A lot. I highly recommend the G&G green buckings for everybody. They also come with a quality nub (I don't use the nubs, but they seem very nice, i Just prefer h nubs or scs's)
