Ok, I've done some more testing. You CAN outrun ALL of your ammo at that speed. Some pretty weird stuff can happen, especially in single player. The wind will "blow" TNTs and exploding ammo away, either to the left or to the right. Using a wind left speed of -128 and standing to the RIGHT of the wind, I found out that if you shoot something (anything apart from TNT) the bullet will travel into the wind and, when it explodes, go almost instantly back to the source (i.e. your gun). If you try with wind left speed 127, the bullet explosion will go straight to the end of the wind events (on the other side of the lvl, 250 tiles away ). TNTs do not work in the same way. The explosion doesn't travel to the other end, the TNT does.

At slower speeds, the explosion will travel quite slowly and you can actually see it moving away. I'm still trying to figure out what kind of differences acc. belt and normal belt have.

EDIT: This sort of effect doesn't work for toasters, peppersprays or electroblasters. I think.