[DonVoigt]

Just a couple things to add:
- the edge and the notch in the bolt look worn- though the pictures are too fuzzy to really tell.
They must be sharp and correctly angled to work correctly.
- I don't know where you can "remove" metal to make the hold go higher??
- Often it is simply a mag that rides too low, if you push up on it and it works- that is the issue.
This may be due to the mag or the mag catch.
- hold open springs, especially replacements, can be too strong
- the button on the mag is too small in diameter on some replacement mags, and original buttons
can be worn, I've seen them flattened from wear on one area, you can rotate the button to a new position

Hope this helps.