I chose the Altaros 49.5's and 60 grainers. Mine shoots the 60's slightly better but its single load only because they won't fit in the mag. The 49.5's will fit using a after market mag adapter system.
The G1 BC is why I settled on them which is .21 and .245 in turn which means half the wind drift of many other slugs out there. I can really see the difference on long range steel compared to the 29 gr NSA's I use in my Uragan 25 cal which have a .075BC.
I'm curious what slugs others have had good success with in these.