Cyma Platinum SLR AK 105 hop up issue

[scrumpy]

With no hop up applied I'm getting about 315fps, but as soon as I apply even the smallest amount of hop the FPS plummets to the 150's. Is this normal or would it be worth swapping out the hop rubber for something softer?

Edited February 18 by scrumpy

[strykerles]

Always a good idea to swap out the hop rubber from standard. Clean out your inner barrel too

[The_Lord_Poncho]

Yes, this isnt normal. That kind of reduction should only happen if you are cranking the hop enough to lift depleted uranium BBs. Assuming you don:t have deep enough pockets to feed that habit, it would seem that either the bucking is torn/nub incorrectly fitted, or something else weird is going on with the hop bucking combo. Either way, the way forward is swapping to a good quality bucking and nub combo - and crucially a combination that is known to play well with your particular hop unit and gearbox/nozzle length (or if there is a paucity of Info on this, be prepared for some trial and error).