I have the lee 12 ga slug mold too, I love it. asfar as accuracy I noticed with lower velocities in using a trap type load with the slug shooting around 1200 to 1290 fps the accuracy lacks, good to 25 yards and just decent at 50 and not very good at 100 yards. If one could achieve higher velocities with these slugs I think the accuracy would increase since most slug barrels have a 1 in 32 twist rate I feel that much weight needs a little more spin for stability achieved by higher velocity. If you know of any loadings that could produce around 1500 fps safely with these lee slugs I think that would be the ticket.