Any help in locating brass for this caliber would be greatly appreciated. Thanks gentlemen!Vintage 40X? 6x47 would be the .222 Remington Magnum necked up to 6mm. Rifling twist will be appropriate for lighter benchrest bullets in the 60-70gr range.
Necks are likely to get a bit short going from .204” to .243”, but it would function I'm sure. You’d need to do it in a couple steps and anneal between thoughOccasionally 6x47 brass turns up. .222RemMag is seen more often.
I wonder if .204 Ruger can be adapted?