When I absorbed my hoarder dad's stuff into my own hoarder stuff, I got, literally, a ton of cast bullets. Quite a few had been in a barn for decades and the various things they were in had deteriorated which, of course, got grit in the lube. I kind of made a vow to myself that Dad had gone to the work of casting and prepping them (I have often wondered if he used to cast and load to shoot or shot to cast and load), so I was going to shoot up what he had cast if at all possible rather than just melt them down and recast. I've cleaned up quite a few and donw just that and after several years, I'm now beginning to see a dent in the supply.
He had cast up stuff for almost every bore size imaginable, fortunately, I'm a gun nut and therefore have something that will shoot damn near any size of bullets laying around somewhere. Finding an over sized .30 in the form of an SMLE or Mosin Nagantwas too easy. Most were pretty easy, pistol bullets of various types. He cast up an awful lot of light .30 caliber bullets in the 100-110 grain range, been shooting those up in various things in gallery loads. Kinda fun, but nothing I take real seriously.