Originally Posted by Kos-Mos (Post 1234442)

Remove your upper mechbox (read thread above)
Check on the side of the cylinder, you will see a hole or no hole. You can move the cylinder with your fingers without opening the mechbox, sometimes the hole is placed inside the mechbox to prevent dirt and shit from going in.

If you don't have a hole in there, leave it that way. You don't need to change it for a barrel up to 540mm.

Be careful with the Prometheus rubbers. They work awesome, but sometimes will have some molding scraps at the lips. CAREFULLY cut theses out with a very sharp X-acto. I looked for the reason for jams in a rifle and it was all caused by a hair-thin rubber shaving blocking the BBs.

Madbull barrels are really good. But expect to see a degradation in performance past 50 000 BBs... that might look like a lot, but I know some people that shoot that much in one summer. If you don't intend to keep the rifle for long, or if you are an occasional player, they are very good. The bore is 6.01 vs 6.03 for Prometheus. In an AEGm this won't make a difference in accuracy or range, but might cause jams with cheap BBs (read here KJW or KSC)


ICS guns all use some standard cylinders. The one you saw might have been a bore-up version. Theses are for barrel lenght from 540 to 650mm (PSG-1 barrels). They will also requite a bore-up nozzle, cylinder head and piston head.

If your cylinder is ported, you can just buy any brand of NB (Normal bore) full cylinder. Modify makes awesome parts and can be bought right off airsoftparts.ca.