[rock_your_beaver]

i have a bl defiant works great but is leaking air down the barrel what could be the problem and how do i fix it

[theintimidator]

the poppet valve could be stuck open i think

[Painthey]

If the gun cycles like normal (bolt and strike move back and forth when fired) but still leaks it could be an o-ring around the valve. Remove the valve, check the cup seal, valve for nicks and the o-rings.

[matt909]

lpr too high

[blue250r]

cup seal is usually the culprit