[DonVoigt]

The "wiggling" is not "headspace; but may be related to an oversize chamber- which may or may not
be contributing to the extraction problem.

The brass pictures are too shiny for me to see the markings, but any significant scraping is not good.

Your cleaning may help.

Sometimes excessive headspace will show as a slightly raised primer- I don't see that in your earlier picture. Too little would "jam" the case mouth into the edge of the cut and would likely be visible, and I don't see that either.

The only reliable way to check it is to use gages.

If you give up after the next outing, and want to send the complete upper to me- I'll try it out by firing on one of my lowers and check the headspace. You can send the complete upper person to person as it is not a "firearm". No charge except return priority mail cost, which is like $7.

You have not put your city and state in your profile, you may be close enough for someone here to help in person.