I guess it depends on the concentration of lead in the berm. There used to be a canyon north of L.A. where a lot of shooters went. I would go there on a weekday (when I was alone) and "mine" lead from the hillside. I had to figger about where the most lead would be (target height and distance from hillside, etc) and the first time I got a coffee can full in a little over an hour. I made a sifter with 1/2" hardware cloth (so .22s wouldn'f fall through) and used a folding shovel and would usually get about a 5 gal bucket nearly full in mebbe a couple hours. I didn't want to get too greedy 'cause I had to lift that bucket into the trunk on my Mustang; heavy...
My Anchor is holding fast!