Need help with hop up.

[Eeyore]

I have a KA M4 with the stock metal KA hop up a Prometheus soft hup up rubber and the hop up bucking that it came with. I am also using a Prometheus 363mm 6.03 tight bore barrel. So at the Mill today irregardless of whether the hop up was on full or was completely off my bb's were zinging towards the ceiling after about 50 ft at almost a 45 degree angle. They had alot of range but I had to almost aim down at a 45 degree angle to hit something infront of me past 50 ft. I removed the nub and the bb's went straight. It was suggested to me that perhaps the soft rubber is gripping the bb's too much and that changing it for a hard rubber while using a soft bucking would fix this. Can I get a second opinion on this please? Are there any other suggestions to level out my bb flight?


Thanks