dud shot once in a while

Sid,
Good thing you should ask. It could be any one of a few things you need to watch out for.

First as you said, it could be a form of valve lock. That can be caused by a valve spring retainer, inside the tank, being a little to loose. But other things are more likely the cause.

Second, it could be using heavy pellets with to low of power wheel setting or in the case of an older rifle that has been carried through the brush may have dirt, leaves, or other debri inside the hammer area sometimes causing a poor hammer strike. Higher power wheel setting or barrel removal, cleaning, and dry type lubrication would be needed. Then, there is the spring silencer, a white plastic tape about 1/4 inch wide by 1inch long that is taped to the hammer spring. It wanders around in there, sometimes peeking out the power wheel adjustment slot. I think if it stayed in the middle position where originally installed, it would be OK and probably dampens a little spring twang. No one has reported any difference in sound after removing the pesky nuisance.

Third and most likely cause of an infrequent DUD slow shot would be hurrying or rapid shooting while NOT setting the cocking knob fully back and to the side. In a hurry it is easy to only bring the cocking knob/breech back to where the o-ring doesn’t get all the way on the top hat thus giving a little bit of a blow out of air that may not be noticed by the shooter.

Additionally, thinking about my learning process, there is also a possibility of putting a pellet in backwards. Especially with lousy loose fitting pellets, the skirt would not be able to expand and provide a good seal.

It amazes me how we make the shooting of an airgun look so simple. The expert doesn’t seem to do anything more than point and shoot.
AMAZING AREN’T WE ❗

I believe the above explaination may be incomplete but if it bores anyone you are probably a natural and couldn’t possibly learn from others.

Good luck and good shooting, Sid :wave: