FX Bobcat MK II .25

"down by the breach' ?

"When I cock the gun and the breach is open you can really hear the air exscaping" , as in the loading/pellet probe is held back/open right? Otherwise the noise would be loudest coming out the barrel? If shrouded may want to remove that and listen or place balloon ( if draining a tank in minutes a balloon will fill ).

IF leaking down the barrel it is the firing valve itself. I do not know the bobcat but did replace a valve stem in a different pcp last night in about a half hour and $15.00 including all seals/O-rings, might as well replace everything you touch.

John