it's been some years (more onto a pair of decades) since i 'ran the numbers,' but i initially went in for casting to save money. i still use my modest litttle melting pot, and most of my moulds are older than my kids, so if you want a good 'excuse,' you can always say you're doing it to save money. right; wanna buy a bridge?
i really do it 'cause it's fun to make stuff, and making your own bullets certainly comes under that heading.
some cautionary notes: you are dealing with lead which is very bad for you, even if it's not being shot in your general direction.
**when you cast, be sure you're outdoors, so you don't inhale the fumes. lead vapor can mess you up.
**when you're casting, wear gloves. this will keep the odd bit of lead splatter (unusual, but not unheard of) from landing on your hands- the resultant burn is quite painful and leaves a nasty looking scar. been there, done that.
**don't forget to put a soft pad (i use a folded up towel, which isn't used for any other purpose and will never go into the washing machine) to drop the balls or bullets onto once they come out of the mould. don't worry if it gets dirty- but don't under any circumstances put it in the laundry, or you'll get very fine dust particles in your clothes. this is bad for your health [insert EPA-type warning tirade here].
**after you're done casting, be sure to thoroughly wash your hands (even though you were wearing the gloves).
**don't eat or drink anything while you're casting, obviously.
lead in peeling paint chips, as we all know, is one the reasons that 'inner city' kids had developmental problems during the last few generations. {avoid political ranting here, but...} this isn't some made- up bs to get another research grant- ingested lead (as well as inhaled lead vapor) causes cognitive impairment, judgemental reduction, loss of reasoning and analytical skills, and reproductive problems, to name a few.
does this mean you shouldn't use it? well, we don't live in a 'nanny state' yet, so luckily, we can assume a few risks, manage a few risks, and still have fun making a perfectly useable product that doesn't harm anyone and provides us with a completely legitimate recreational activity: it's just not something you want to do in your basement.
have fun, but be safe!