Lowering a KWA GBB MP7A1's fps?

[HellJumper]

Hi, I've recently bought a KWA MP7A1 and it's shooting slightly hot for my field (380fps, my fields limit is 350), so I'm looking at ways to lower my fps. I'm open to most ideas and not afraid to do some tech. 

 

[Prisce]

Which gas are you using? 

 

[HellJumper]

Green gas

 

[Prisce]

I think, don't quote me on this, Abbey 144a gas is slightly weaker so may drop your FPS just enough. Other than that, I'm not very clued up on the internals of gas guns, think this may be one for the Proff. @proffrink?

 

[Aunty Pasty]

The 144A gas should be enough to reduce your fps and is the easiest option. Alternatively you can fit an adjustable gas nozzle to lower the fps.

 

[HellJumper]

I was thinking about buying a MP7 npas valve but I'll try the 144a gas first. 

 

[alex90]

I tried running 144a in my kwa mp9 and wouldn't cycle the gun very well and kept locking the bolt up and venting

before I converted to HPA I ran these

  http://www.ebay.co.uk/itm/Airsoft-CNC-Machined-Power-Down-Valve-Set-For-KSC-KWA-S7-NS2-MP9-MP7-/141409941879?hash=item20ecb07977:g:rCAAAOSwGvhUGNbn

bit of a pain to fit but worked a treat plus you get two to try ones about 20fps drop and the other is about 50

 

[alex90]

and I was using a mix of aim top gas and WE neprol gas