There's obviously (now it's obvious...sorry for your luck) something wrong in the setup. Not necessarily a "trying to fit tab A into slot B" problem, but there's some kind of tolerance thing involved.
Another odd ball kind of thing that could be happening...
- the chamber that you're using may not allow the nozzle to seat properly...even if you've got the overall length ok.
If you let the bolt go forward slowly/gently by hand...does it seat fully?
Anyways...if you're just guessing at things, better off to get it to someone who might be able to make better sense of it.
Or ruin it completely...I'll buy it cheap for parts afterwards...
(just kidding)