There has been plenty of discussion about DeRuitter and his unfortunate demise.  It has pretty much been determined that he was using reformed .30-40 Krag brass (GENERAL WARNING: DO NOT USE KRAG BRASS IN A LEE NAVY) and perhaps a double charge of pistol powder in a "reduced" load.  Krag brass was also responsible for a Lee Navy being destroyed a couple of years ago.

So go ahead and buy yourself a Lee Navy.  There are safe loadings out there.

Good shooting.