Hello Pete.
I played around quite a bit with this stuff and had very good luck with the 3" Brenneke and lightfield hybrid slugs. Both grouped within 2" or less at 100yds.
This was with a slow twist rifled barrel. I moved to the Lightfield to avoid the slight leading issues with the German slug.
I don't have any experience shooting game with them yet, but I plan on it this winter.

Cheers
Tom

Carbonation without fermentation is tyranny