And that, may friend, is the name of the game!
Ahhh... the "spray and pray" approach. I used to do that, and it is a lot of fun. But games often go to stalemate that way; with each side behind cover, at sufficient range that they cannot get an accurate shot on target, because the BB's are out of energy, just dropping. Which is when a well tuned gun, is worth every €uro you have spent and more, because you can pop someone who only shows his gun and head, and do it quickly, which is important, because once they know you can shoot that far, they will not sit there looking at you so long!
But to get that performance, you need very consistent power, which requires a better air-seal than any stock gun is supplied with, and very stable hop up, which few stock guns have, and even those which do have it, lose much of that stability in the barrel. Plus you need quick trigger response, which requires a gearbox cycle speed of at least 18/s, which is faster than most stock guns, unless they can use 11.1V LiPo batteries. Most stock gearboxes will wear out fairly quickly, if you use an 11.1V battery, and those which do not are actually not cycling that fast anyway - much of the battery energy is being wasted on high resistance circuits, and poor friction characteristics of gears, shims, piston, etc. so, although they are cycling faster than average, say 16/s, that is still not impressive, when you consider that a good rewire, MOSFET, grease, and shim job, will get that from an 8.4V NiMh battery...