Proper thickness of brass at back of .300 RUM

[Tadman1]

I am relatively new to the forum, so I hope this question is in the right spot. I just ordered and received 50 pieces of .300 "once fired" RUM brass from Gunwerks. When I opened the box, I was surprised at how much wear appeared at the back of the case (for once fired brass), but ignorantly proceeded to resize them...and trim them. They all measured at lest 2.846 after resizing. Several of them became creased in the redding resizing die, so I back the die off the shell holder a little bit and cleaned the inside of the die. After several of the resized and trimmed cases wouldn't even come close to allowing the action to close, I noticed the excessive wear at the back of the case....possibly where the web is located..but I am not sure. The R-P brass that I have fired in that rifle measures .0548 at the thickest point and this brass (well 32 pieces of it anyway) measures between .05505 and .0552. Is this extra .0025 - .0040 enough to prevent the bolt from closing? I have sent Gunwerks a message asking if they had any suggestions or if they accidentally sent me brass out of the "many times fired" pile instead of the "once" fired pile..... I guess its possible that someone was just shooting loads so hot or in such a loose chamber, that these cases just won't work in a custom chamber....Hopefully someone here or someone at Gunwerks will be able to help me figure this out. The $75 shipped seemed like a good deal until I got the first casing stuck in the gun.