Newbie PCP question

[Dennis250]

I just received my first PCP Diana Stormrider in .177 Gen2 ,   When shooting from the single shot try I get a pretty good puff of air hitting my forehead, is this normal?

[Ribbonstone]

This is the pre Diana version....and a generation 1....but there should be an o-ring in the breech that seals against the closed bolt.

Sometimes they crack/fall out or otherwise get mangled or jected (like a double feed or a miss feed from a mag).


Looking with the light over your shoulder with the bolt open will let you see it (might be brown like the one below,but more likely a black o-ring that's harder to see):

[Dennis250]

well that explains it,  there clearly is no o-ring in the breech of my rifle,  this also explains repeated jamming from the Mag

Thanks for the quick response