Bullshooter,
You might want to reconsider the choice to buy nickel plated brass. My expreience has been that it's hard on steel dies and if not really clean can scratch carbide dies. Just my opinion though.
You might want to take a look at your buffer spring. The buffer spring is in the buttstock and is what stops rearward bolt travel. It also returns the bolt to battery. I had a similer problem with a gun built from a parts kit. The spring supplied with the kit was too long and did not allow the...
Good luck with the case rims, but my experience has been that when the rims are bent firing them will not straighten them out. It will misalign the chambered round and give you fliers though if that's a plus. I think you should consider scrapping them out as Bill suggested. I had a bunch of 7.62...