If factory ammo is doing that too, I would take the gun to a gunsmith and have a chamber cast made, and the measurements taken off the casting. If it is out of spec, then it is your chamber, not the brass. You have to remember, they chamber as many barrels as possible before changing reamers at the factory. If you get one chambered towards the end of the reamers life, there could be issues. Just a thought.
This was my first thought....chamber out of spec.
Nobody wants to hear this, but I don't buy Remmies for this reason.