One of the website that influence me was this one:
http://www.planetairsoft.net/reviews...-kjelitem9.htm You can read this: "You can install the usual gas blow back pistol upgrade parts on the KJ Elite including: Hi Flow Valves, TN Barrels, Stronger Recoil Spring or Stronger Hammer Spring" I also saw on an other website the 400fps.
It is also funny to look for the real fps of the gun. It vary from 250fps up to 400fps on some site (with a mixed of green/red).
I bought it from Anderson and Anderson for 259$. I choose this gun because of the reviews, the fact that it was a full metal for such a low price.
The gun itself run flawlessly (after 1 bottle 1/2 of propane), it's strong and look really good. It's just that I really love to upgrade all the toys I have, whatever it be a car, and rc, a computer etc ^^