Any experience around here with a simple neck down on 7 Rem mag brass to 270? A buddy is thinking of a custom reamer running the 170 eol in an 8 twist Proof Research carbon (he has them to build with). Powders, limitations, cool factor etc... I'm sure it's been done a few times and I'd like to hear some thoughts. For some reason he really likes the Howa action. He also does all of his own machine work and is **** good too.