Thank you for all your replies, I took the rifle apart to change the seal's piston and breech, and when I pulled the breech seals out first one came out ok with a dental pick the second o ring came out also the small metal orifice that is I looks like it is pleased into the large nut that is screwed into the piston chamber.
I have since used some lock tite and pushed it back in with new o rings left overnight and shot it with the same low fps, so that was not the problem.
I have ordered a new spring hoping that is the problem. I did push on the piston with my finger over the end of piston chamber and it held the air good. Thanks. Steve!