Re: 300rum brass????????
There is a place D&L sports in Wyoming that has Federal 300 Rum brass. Run a google search and it should come up.
To be honest, my experience may not be the norm, but the remington primer pockets are much tighter than the federal. I haven't measured neck inconsistencies in the federal, in that area I would suspect it is better than remington. I was getting 4 firings from the remington, might could have gotten one or two more, the federal after the first firing the pockets are very loose. I have shot some twice but I have not tried to load them a third time(just due to time) but I don't know if theyll be tight enough for another firing.