They are a fine company. The 18 BHN is hard but many companies offering machine cast bullets are much the same. Most use 92-6-2 alloy because it is the perfect casting alloy. You 'bout have to try if you want to make a bad casting from the stuff. I've probably used close to 10 tons of the stuff over the years. Air cooled this alloy will test 15-16 or when water dropped, 18-21. Hope this helps.
Dry Creek Bullet Works
Dry Creek Firewood