Classic spyder paintball

[FEZ1992]

I just bought a classic spyder I changed all the seals on the gun with new o rings but my gun is leaking air out of the barrel not sure how to fix it

I already own an Tippman A5but hav not encountered this problem before need alitte advice

My gun almost looks like this one except I don't hav a black barrel and Mine has a double triggerhttp://www.google.ca/imgres?imgurl=h...ch&um=1&itbs=1