Why would anyone in their right mind make or especially, shoot a pistol chambered in 600 NE? I dont even want to shoot one in a rifle, much less a pistol...
I'd say the FIRST thing ta do is gradually work the load up so ya KNOW what to expect.
The second - don't be so stupid as to build a gun like that, then let SOMEONE ELSE shoot it!(yeah - the the "rest of the story" is that it was a custom, 1-off gun built for the hell of it that he let his "buddy" shoot - you see the results)