plus the time to go get it. 12 hours, at how much for your overtime pay, john? $50 an hour? With a $100 plumber's furnace, you could do the entire batch in an hour. Think I'd pay some kids to do the testing for zinc or aluminum. a magnet should suffice for the steel ones, real quick. Still melt small batches at a time., and setting some out to harden, to look for the telltale "wrinkled AND frosted" look that says it was both too hot and too cold, which means it's contaminated. I just pour 10 lbs out on the concrete floor of the storage, then chop it with the axe. The cast iron pot is a foot across at the top, no need of small chunks. Leaving some liquid lead at the bottom of the pot speeds up each melt.
When I smelted down the 3000 lbs of wheelweights back in 1978, it took me an entire weekend, about 30 hours. I made some of the muffin pan ingots, but mostly the 20 lb pot-ingots. I did some of the casting in Joe's garage, when I paid our bills with it for a month or so, the second time Kay left Bob to be with me. I was getting $30 per 1000 for the 230 gr H&G swc's. about 13c each in today's money.
That was a good bullet design, if I do say so myself. I shot quite a few sub-3" groups at 50 yds with that bullet and 4.5 grs of Bullseye, even tho loaded in old brass on a Star Progressive machine. The practice MkIV that I had had a broken a collet bushing in it. Wilson let me take my pick from a big boxful of collet bushings that he had in his shop.

He told me what to beware of. What breaks them is having them expand to too tight a fit in the slide. wedging them around the dog-knot in the barrel's OD.
That's all it took. No fitting of the slide to frame, or barrel hood/bottom lugs to frame. Some had 3 holes touching, firing prone at Harry Claflin's place near Bronaugh, MO. Bill came up to shoot one of the World shoot's assault courses there. I had it set up and was practicing it a lot. Bill had his range tied-up with other courses.
My match gun at the time, Bomar's, a fitted NM barrel and bushing set, fitted slide, etc, would deliver sub 2" at 50 yds, 5 shots, on my Lee Machine rest, with match grade reloads with that bullet (new brass, loaded in an RCBS rockchucker, weighed charges, weighed bullets, etc. It would do 1.5" with Remington 185 gr jswc match ammo. I owed both of them to a guy in S Africa, who bought my plane ticket. He got them for well under half of the going price in that country at the time. I was ignorant of that fact. The practice gun had had about 30k rds thru it. Had a tiny crack near the slide stop hole. I'd had to replace a couple of old GI mags, that bushing, the firing pin stop, and the extractor (both broken by wax-loads/dryfire.) LOTS of dryfire, 1000's of clicks per week, hundreds of magswaps. So, yeah, i do NOT want to mess with DA or Glock trigger pulls. No real benefit and "undo" all that training? no way in hell.
If I'd known to get another school loan, 1k or so at the time and take two suitcases full of primers with me (5c each at the time, in SA, cost me 1/2 c cause I'd bought 100k of them) I could have hunted private ranches there for months on end.

But I was nuts about Kay and when she said she'd leave Bob if I came back to the US, I went. Biggest mistake I ever made. If i'd known at the time how to make silencers, I'd have stayed there and been rich, long ago. I could have wholesaled them to gunshops for $150 each in today's money, by the 1000's per year, paying others to do most of the work of making them.