You can cast bullets from that alloy. Lead shot is about 13 bhn, a little harder than wheel weights (12 bhn). Most of the bullets I cast and shoot up to 1000 fps are cast from wheel weights and 1-2% tin. You might want to add a little tin to the shot to improve castability. The tin you can get as lead free solder from the hardware store, its 95% tin. If you are casting a 200 gr bullet, you will get about 1000 bullets from that 30 lbs.
Do you know what kind of shot it is? The two common varieties are "chilled" and "magnum" (also called hard, extra hard, and similar.)
The chilled shot is generally around 2-3% antimony, and, though I don't have the Brinnell numbers in front of me, will probably be ABOUT as hard as straight wheelweights. (See Cherokee's numbers above.)
The "magnum" varieties are usually about 5-6% antimony, and should produce bullets of a hardness range similar to Lyman's No. 2 or the newer version of that alloy often sold as "hardball" (or similar.)
I haven't tried casting bullets w/ lead shot, but have played w/ one of the Littleton shotmakers when they first came out (we fed it our reclaimed shot from the range, which was a mix of chilled and magnum.) That limited experience tells me you'll PROBABLY have enough tin in your shot for decent castability, but only trial and error will tell for sure. You MAY want to get some of that lead-free solder, or some pure tin, and add a bit until you have the right alloy for your use.
Dunno if you can find pure tin locally. If not, I've gotten metal from www.rotometals.com. Tin used to be cheap--but is no longer--so use it sparingly. About 2% (by weight) is all you'll generally need to make your alloy cast nicely. Since there's already SOME in the shot, a bit of work w/ your calculator might be required to figure how to bump your mix by maybe 0.5% at a time. Also, if you're using alloy molds (like the Lees), you may find running the alloy a bit hotter will improve castability more than additional tin.
Finally, I can't prove this to be true, but have read and been told shot sometimes has some arsenic in it, which commercial alloys don't, so be sure to do your casting outside in plenty of fresh air when melting it... just in case!
Thank you for the replies. I do not know what kind it is because we dug it up from my buddies front yard. The guy that used to live there owned the shooting store in town and when he would get a ripped bag he would dump it in his front yard :?: We probably dug up 150 lbs a few years ago.
I would clean and save the shot for shot caps for my .44mag and .45LC. Lots of fun there.
I have varmits from wood bees to rabbits with handloaded shot shells. I wish I had a dollar for every rat I have killed with them, I could retire. 8)