Feinwerkbau 300S (FWB 300S) Anomaly?

I have a Feinwerkbau 300S from 1976. I recently had a breech seal failure and replaced the seal with a new green FWB factory seal. After replacing the seal I noted that it took considerably more pressure to close the breech after cocking. I would not consider it to be forcing the breech closed, but more than I expected even with a new seal. When I attempted to fire the gun with the trigger, nothing happened. Being wary of anything that tosses a projectile, I pointed the muzzle in a save direction and pulled the cocking leaver back, out of battery. The gun instantly fired. I tried this several more times with the same results. No trigger and a discharge when the leaver pulled the breech out of battery.

I located a used, but nearly new, blue, breech seal and replaced the green one. Everything is back to normal except my confidence.

This, of course, brings up many questions...... Anyone else have any of these issues?
1. A green breech seal simply not fitting properly.
2. A dead trigger.
3. A discharge upon bringing the breech out of battery. 

I am a very old had at firearms, but a near total novice to airguns.

Thanks for any help.

d
 
Azuaro,

Thank you for your interest and advice.

I seem to have solved the problem with a little judicious fitting and a bit of trigger adjustment. 

I spent some very pleasant time hand fitting the new green seal to get it to fit just right. It seems that, both the blue seal and the green seal were protruding just a bit. The blue a bit less than the green. I carefully trimmed the rear of the green seal until it fits just slightly lower than flush. 

All seems to be working fine. I am enjoying a very nice trigger and see no indications of any air leakage around the seal.

I am shooting inside and need to get better lighting over my chronograph before I can gage velocity, but all seems well. 

Thanks again.