Hey 600jdj,
I'm guessing the picture shown is a 600JDJ...impressive to say the least. What have you got that chambered in? I would think just about anything would expire very quickly when clobbered with that much lead. Just actually what I'm after!
When you talk about the 600 AHR is this the 600OK? Is there a website or good links on the Overkill. Maybe this is what i'm looking for. I liked the look of the Nyati because 577 cal bullets are readily available and Bertram Nyati brass should be easy to get. Maybe even the 550 Magnum might be the go. That way it is just weatherby brass straightened out.