So it seems to me like my spend casings are crimped/dented on the side after ejection. I noticed after shooting a bunch of rounds that the crimped part/dented part is actually having pieces of brass being shaved off of it at some point in the firing/ejection process and it's spreading those shavings all over my Luger. It gets everywhere and it's scratching my finish

I thought I read somewhere else on this forum that the crimping of the rounds is normal, but lugerdoc said it wasn't. I've been using WWB but it does this for all ammo, honestly.
I stopped using the original mag once I got my 2 new mec-gar magazines but those don't seen to help this brass shavings problem.
Also, 50% of the time the action doesn't like to stay open after shooting the last bullet. about 40% of the time the action stays open with 1 bullet remaining. What's going on with that? It's happening with my 2 new mec-gar mags and my original mag. Here are some pictures. Sorry for the massive size and bad quality. I just want to get this fixed!

it does this to all the ammo, although sometimes it's not that crimped/dented. Most of the time, however, it's pretty dented.

as you can see here, the casings are pretty dented. Not sure if this is normal

this is where the majority of the built up is. The brass just grinds in there and scratches everything

As said earlier, this stuff gets everywhere including all down into the grip area.

here's some of it on my original magazine.
Any kind of help/suggestions would be greatly appreciated!!