Cyma028-AK FPS drop when turn on the hop up

[BXZ]

Just got a new cm.028 AK.

When I turn off the hop up, the gun is shooting well with around 315fps without any problem. However, when I turn on the hop up, the FPS drop very significantly. I think 260 fps when half of hop turned on and 220 fps when the hopup is fully on. Is it normal to CYMA AK? Is there any way to solve this problem (like upgrading the bucking)? Thanks!

 

[Asomodai]

Perfectly normal. On some rifles when I turn the hop fully on it goes into double figures. It just means you have a wide range of hop adjustability. Would rather too much then too little.

 

[SSPKali]

As Asomodai says, the FPS drop is a by product of the hopup giving more backspin to the BB (by pressing on it more)

I chronoed my Cyma AKS-74U once with the hop in full and wondered why it was only 150fps! Then I remembered I had stripped it down and the hop always gets pushed on max when reassembling! Turned it off and back to 330fps ?

 

[BXZ]

ok, it sounds good. Thanks guys!

 

[Rogerborg]

That does sound like a lot, but the question is, what's it's shooting at with the hop dialled info for the weight of BB that you're using?