I'm just starting to look into loading for my inbound 20mm Anzio.  Does anyone here know, for sure, if there is a difference in the primer pocket for electrically primed vs. percussion primed?  Before I go buying ridiculously expensive brass, I want to make sure I'm getting the right cases.  Any additional info at all on loading for this beast would also be appreciated.  I'm looking at going  the route of the bushing in the primer pocket to reduce for a 50BMG primer and then doing the black powder trick on the primer for proper ignition.  I would like to use a slower powder than the gobs of WC867 I have but may end up using that.  Got everything I need but the brass and the bushings.

“Definitely”  hit that last Knob Creek machine shoot in October. For the fun and lulz of the final crowds
  Aaand you can make some excellent contacts from there. Life long contacts. A lot of great folks there