I just got another 10 lbs of Heavy Weight 13 #4 shot from Bucks Run Sports Supply. It is just a little denser than Hevi-Shot at 13g/cc.
I got 10 lbs shipped to my house for $196.50. The last bag I got was Heavy Weight 13 #6 shot. This shot looks much better than Hevi-Shot, it is round and the size of the shot looks very consistent.
You can reload 142 shells with 1-1/8 oz of shot in them out of a 10 lb bag of shot. So that comes to $1.38 per shell just for the shot. This seems pretty expensive but when you compare what it costs to reload these Heavy Weight 13 shells to what Hevi-Shot Factory loads cost, reloading them is a good deal.
I think the Hevi-Shot at BPI is $229.00 for 7 lbs plus shipping.