The o-rings from the hardware store are round, the breach seals are taller than wide(the shape of the seal itself). You likely are not locking up tightly enough and should check your alive jam/...or the seal does not protrude enough to have a good contact. The jam is easily removed by putting the breach down on a firm surface and by pressing down to release the pressure on the bushing, you can slide the jam out and place a washer behind the spring to increase pressure. The seal can be easily shimmed outward by putting a few wraps of dental floss under it before it is replaced.pv