Forse sui fucili brass tube il problema non era/non era solo l'hop-up...
Da GGi:
Sorry for digging this up, but I just saw this discussion. It really is not the case as far as the closed bolt system goes. I mean - the hop-up has nothing to do with the inacuracy, reagrdless if it's a stinger or a stock version hopup unit.
The problem indeed is a design flaw, but it has nothing to do with the hopup. The real problem is that the magazine lips do not sit hight enough. Or said otherwise - the magasine does not enter the well deep enough. So when the nozzle strikes forward, instead of picking up the BB from the magazine and loading it into the hop-up unit - it literally smashes the BB against the brass tube's rim. Some of the BB's break, the ones that don't - deform, and naturally - after leaving the barrel, fly all over the place.
This forunatelly can be fixed easily enough. I fixed this problem by simply adding a thin rubber spacer under lips of the magazine, elevating them and the gas port just some 1.5mm. The Scar started shooting straight and true.
A also sanded down all the sharp edges in the brass tube, but that's an extra - really the problem is in the vertical positioning of the magazine.
Actually that is why the majority of the WE Scars seem to be experiencing problems with the bolt stop: it just is another symptom, pointing at the mag's vertical position. It simply sits too low, and just a little wear on the pusher is required to virtually disable the bolt stop function altoghether. Fortunatelly - that is easily fixible too
seeing the new open bolt hopup on some the photos, I conclude that the problem with the vertical position of the mag is eliminated, by using the single stack magazine lip and the pistol-type polymer nozzle. Fair enough - it's a proven design that functiones flawlessly on nearly every GBB pistol.
