VSR-10 airbrake question

[Igilmour]

I have a question regarding the TM BSR-10 G Spec. I have all the necessary parts to take it to around 360fps (m120 spring and trigger sears) but I am wondering how much of a difference the air brake makes to the power output. I have read that it can take anything from 10-20% of the springs power away. Is this correct? I can always remove it if I need to. Cheers.

[Samurai]

Or much much more, depending on the barrel length.

But the air break is there for a reason. It cushions the piston on the last few mms. The gspec has a very short barrel so as far as I know it won't make much difference in fps because by the time the piston reaches that part where the air break works, the BB is already out of the barrel. And without the BB's resistance only the air break keeps the piston slamming full power into the cylinder head (and that's bad).

[Igilmour]

Cheers. I'm going to experiment once I get the spring and stuff anyway. If it keeps the M120 spring below 360fps I'll be happy.