Hop up in my sniper?

Hey guys I am quite confused on how to adjust the hop up in my sniper rifle, it's the WELL MB05 (or G-22) and I can hit a man sized target from about 180 feet out, now the thing is though is that my bullet drops about 6 feet from my shot point, for being out 180 feet from where it was shot, is it right to drop that low or can I fix that to make it hit my target without having to aim above it?
gun shoots presumably 450-500 fps according to the airsplat review ( review is not by airsplat but an actual airsoft reviewer )
This is what is looks like
Courtesy of Airsplat.com




The hopup is set in the barrel and needs to be pulled out to be worked on

BUMP
does no one know how to to adjust a sniper rifle hop up?

In the middle pic, there is a black set screw.... You turn that with an allen key(I forget what size is needed).

sticks

Thanks sticks! =]

i have that same sniper and it is a nice sniper in all but the stock is a piece of crap. my stock is beginning to crack and has some chips where it is being held together. but sniper004 upgraded his L96 so ask him...... (the mb05 has the exact same internals as the l96)