[BenG]

your hop up is misaligned. The reason your gun still shoots straight up to about 30ft 50ft whatever is because essentially all of an airsoft guns range and accuracy is due to a physical phenomena known as the magnus effect, which the hop up is responsible for. Essentially by spinning the bb you create an area of low pressure above the bb and an area of high pressure below that counteracts the effects of gravity on the bb (exactly the same way an airplane wing generates lift, but a wing does it using a special shape). when the spin is not vertically aligned the force that keeps the bb in the air now pushes it in whatever direction the y axis of rotation is on. Anyway the reason your gun shoots straight for the first little bit is because the magnus effect only works at low speeds, so basically the distance the bb travels straight before curving is the distance that the projectile is travelling to fast for the phenomena to occur.

The fix is simple, pull it apart and make sure that the hop up is pushing flat into the barrel, or if its pointed slightly as stock hops tend to be make sure the "point" is perfectly centered.