I run a 7mm SAUM and run Rem brass, tried necking down some 300 Norma, but had to take 1-1.5gr of 2217 out of it to not get ejector marks. I had enough Rem brass to last a little while longer so im still using that - Its definitely a lot harder.
I did weight sort all my rem brass, and noticed the same large variance in weights as you. I just batch it, and it shoots .5-.75 MOA which is good enough for me.
I run a stiff load of 2217 and get 3k from a 22" barrel with the 162 Amax, which is pretty hard on the brass with primer pockets loosening up reasonable quickly, im sure if i backed the load down a tad the animals wouldnt notice, but its just so dam accurate at that load.
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