Thanks, Scott.
My design is based off the old 7x42 cartridge that can be formed from .284 brass which Lapua makes. I believe Lapua's 6.5-284 brass would make the best parent cartridge. My intention was to have a case capacity somewhere between a 6BR and a 6x47 Lapua. I was actually thinking of making a deer rifle out of it before taking the plunge into a 600yrd rig.
. But my next 4 targets were all 4 +1's
.