So I recently bought a tokyo marui mp5 a5, it works great but is missing a battery and has slight cosmetic damage. I opened it all up and got in the gearbox, it was fairly dirty, and everything was stock. Seeing as I didn't want my gun to shoot 260 FPS. I then decided to upgrade it, I was planning on getting a lot of stuff, including the AIM infinity tornado gearset with piston. Would anyone here have any experience with these? I was wondering if they are worth it or not. Also any other info I should know about what parts I should put inside the gearbox?
Here's a link: http://www.airsoftpost.com/product_info ... s_id=29526