Beeman/Weihrauch HW 100 problem

[Neil_Ind]

Has been more than a couple years since I stayed in touch with this great forum (busy retired life!😮) But recently I had discovered a leaking air cylinder in my .177 cal HW100. Could find NO ONE in the US that sells O ring kits for it. Had to order from Poland, no biggie, but it took a long couple of weeks.
Fast forward to this morning, finally getting around to installing the rings, put the gun together, aired it up.....YES!  It holds air pressure!!!!!!
Then, that first pest bird tries to bully in on seeds for my songbirds....I get the Hw, and.....NO pellet leaves the barrel!!! Gun makes a sound as if some air has gotten to the chamber but the pellet is stuck in the barrel!!!! WTH??? I did no other breakdown of the rifle other than the air cylinder as that was were I had found the leak. Now what??!!!! The main air seal o ring which is on the air cylinder- rifle connection seems in good shape, no flattening or other distortions. HELP!! Why am I not getting enough air to push the pellet downrange??  Thanks in advance for any/all suggestions and help.
Neil