I had one hint or tidbit that will give you a jump on the whole casting shtick. If you take your collection of COWW (Clip On Wheel Weights), and sort out all the none lead ones, you will have a pretty decent alloy to cast most pistol and rifle bullets. When you melt them, bring the temperature of the melt up to 620 F and flux, you should have a fairly clean alloy to work with. All the dirt and steel clips will have floated to the surface shortly after melt occurs and they are easy to skim off and discard in a metal container. Anything foreign or not melted at 620 F should be skimmed off and discarded. After the first flux there will be more dross to skim off. The trick is not to exceed 620 F by too much for smelting.
After smelting I pour the alloy into ingots for later use. To cast I take the ingots and melt them, again bringing the temp up to 620 F, after which you can flux and skim or skim first if the alloy melt has too many foreign floaters.
When melting ingots, the most common advice is not to skim off the dross before fluxing as you will "loose the valuable alloying metals, tin Sn and antimony Sb". Although true, it's been my experience that after the initial smelt, on the first melt if you skim at 620 F, you get a much cleaner alloy. Usually, there is only a spoon or 2 of discard, and I've found that the melt is a bunch cleaner. After that the standard flux and skim work fine.
When you are ready to cast, raise the temp to about 700 F or to whatever temperature gives you good bullets, but try not to exceed 750 F, which is approaching the temperature at which lead vaporizes.
There is a lot more to it than that, but this will fast track you, and get you decent bullets.
Alloy analysis is easy with a XRF gun, most recycling depots have one, and you may be able to find a business near you that has one. My preliminary search did not find any near Winnipeg.
There are telltale indicators of alloy composition, bullet weight, hardness, smooth sprue, fractured sprue, shinny bullet, dull bullet, bullet detail and so on.
If you cast with COWW, you can get harder bullets by heat treating. Another trend is to powder coat your bullets, which will make a cast bullet behave like a plated or jacketed one, or so I've heard. I do not powder coat yet.
When I started down this rabbit hole, I bought cast bullets from commercial casters, learning how to load and shoot cast, and to find suitable mold designs. Most molds are expensive (the iron ones), and you don't want to buy a bunch just to find the right design for your application. There are cheaper molds (aluminum), that work OK, and perhaps that is a good way to get into the game with the least amount of cash outlay. I have both iron and aluminum molds, each has their idiosyncrasies, and each will make bullets.
Buying used molds is a craps shoot, and can be a pig in a poke, I don't like to pay too much, as there can be issues.
I'm very new to the casting game, and far from being an expert, but I have had some pretty good successes, like a 150 gr Loverin bullet that shoots like crazy in my son's 7mmx57, a couple of good 30-30 bullets, a 38-55 work in progress, 357 and 44 handgun bullets and some nice 35 Rem bullets. Most of my successes are of the gas checked design. For the beginner, good results are easier with a gas checked bullet. A plain base bullet bullet seem to require a bit more planetary alignment and Zen at first. After you get the scientific stuff out of the way, the rest is more of an art.
There are a few scanned books out there, search for "cast bullets by Harrison, NRA" and the LASC site is good as well. Also search for articles by Fryxell, Harris and Kelter.
Safety first, you are working with 700 + molten metal, you do not want a visit from the tinsel fairy. Welding gloves are inexpensive and a leather welding jacket or leather apron is also a good investment. Face shield, welding cap, work boots, and whatever else you think will keep you safe.
