gun wont shoot under 300fps

[slap003]

at 300fps my gun shoots perfectly. when i try to get it any lower i can hear air every time i pull the trigger but i dont get the 'pop'. how can i trouble shoot this?

i have 1.5 carrier, 2 shims, and middle spring.

thanks.

[Gotcha3]

See if you can go to the next smaller carrier (You may need to because the PT Piston and the carrier oring have too much friction between them--therefore the only way to accomodate for this problem is by cranking up the velocity) Use the largest carrier that doesn't leak. On top of this, the spring may be too strong for that tight set-up you may have between carrier and PT piston--again--larger carrier may solve the problem. If this doesn't work--you'll have to let everyone know what your input pressure is on your tank and any additional info that may be needed.
Hope this helps,
Aaron

[joeyjoe367]

toss in the next smaller spring.