Just purchased a new Ruger Guide rifle in this caliber and looking for some new brass. Plenty of ammo for sale but I prefer to load my own.

I have not found any. I would write or call Hornady. Maybe if enough of us do they will do run. I bought a 375 bullet puller. When my present brass is done I will buy loaded and pull the bullets! Good luck

Pretty sure you can make passable brass by expanding the neck on 300 PRC brass, FL size and a fireform. Lot of quality PRC brass out there.