If your hop-up adjustment is not having a big effect on the hop-up of your BBs, then it probably means that your hop-up packing is worn down and is not gripping the BB properly before it is fired out. A new hop-up packing will allow more accurate hop-up adjustments. Best used on guns that shoot above 400fps. If your gun shoots below 400fps, then opt for the soft type hop-up packing instead. Especially recommend using this hard type hop-up packing onto upgraded AEG.