tried to search it...

[Steveothegringo]

what exactly does the hop-up change? I see people say turn it clockwise or ccw, but what exactly is that changing?

[ThatGuy]

The hop of the bb
A simple Google search would have told you that .
Also shooting the gun and turning the hop up would have told you that.

[theFlyingTrumpet]

You ever seen a curve ball thrown in a baseball game? Yeah basically that except curving upwards instead of left or right. Like KillerDragn said, to counteract the effect of gravity.

[theFlyingTrumpet]

You know I bought one of those Madbull buckings that came with the fishbone nub, which supposedly pushes down more evenly on the bb. But, the nub wouldn't fit in my hopup so I basically had to cut off edges of the nub which gave me a standard looking nub.

[theFlyingTrumpet]

I seem to have a pretty accurate spread with my 363mm length 6.03mm barrel and Madbull Shark bucking, but I don't really have anywhere to actually shoot down here near campus so I don't have anything adjusted correctly. My red dot is more of a suggestion on where to aim.

[INFIDEL]

I have the Madbull Ultimate 3 in 1 Hop-Up and Im running the fishbone nub in it ATM and i think it makes a greatly noticable accuracy difference. very nice hop-up unit and nub. recommend 100%