Is it worth upgrading these parts?

[Kevin32]

I'm kinda new when it comes to AEGs, getting my first one soon, when I get my paycheck.

Would anyone recommend a Systema BS Precision Barrel, a Systema Air Seal Nozzle and metal bushings?
I'm thinking of slightly upgrading my gun after I get it, upgrading the FPS without upgrading the spring, I've had several guns before (springers and springer rifles, just for backyard plinking though).

I've messed around with barrels before, but not any air seal nozzles or bushings, so how hard is it to upgrade the bushings and air seal nozzle, recommended for someone who has not taken apart an AEG before? I'm not planning on upgrading at once, but I'm planning for the future.

Kev, the upgraded barrel and air seal nozzle will help get your fps up....but only a small amount. Add a systema silicone piston head to help.
Dont need the bushings unless your uping your spring.

[ILLusion]

Air seal nozzles do not increase FPS.

They are used to mate with aftermarket cylinder heads to get more efficient seals in order to provide greater velocity consistency.

Metal bushings do nothing for velocity and aren't required unless you're increasing the strength of the spring either by putting in a stronger spring or even adding a spring guide with bearings or both.

If you want velocity increases without upgrading the spring, put in:
- spring guide with bearing
- metal bushings
- tightbore inner barrel. The tighter the barrel, the higher the velocity gains, ie Prometheus 6.03mm. Also switching up to quality BBs with large diameters will increase your velocity. In order of largest to smallest of the three largest brands available are Guarder, Airsoft Elite, KSC Perfect.

Ventilating your piston head will also increase shot consistency and may also give a slight boost in FPS - best of all, that's a "free" upgrade.

Upgrading to an aftermarket piston head w/ bearings and using it with your stock spring wouldn't be a good combination - the stock spring has a hook on it that needs to be removed if you want it to sit properly against the piston head's bearings. The thing is, by removing that hook, the spring will end up having a lower pre-load, which results in lower FPS. The reason why this is, is because the stock piston head's nut is almost twice as thick as aftermarket piston head's bearings. The thicker nut ends up compressing the spring more, and thus, gives you a higher velocity.
You can leave the hook in place and you'll actually get a higher velocity that way, but the spring will not sit properly against the back of the piston/pistonhead and can put pressure on the piston/gearbox rails in unexpected ways which lead to minor consistency issues, ROF issues, and battery draining issues.

Upgrading bushings can be a pain for someone who's never done it before as you'll need to re-shim the gears after doing so. We don't know what your mechanical aptitude is, so saying it's "hard" to upgrade a gearbox is relative. I would say it's easy. Others would be left scratching their heads.
However, it's safe to say that shimming gears is the hardest part about gearbox modifications/upgrading. You'd do best to do your research on that before attempting it.