Bet they run 1-2% Sb. Melt em down and flux, flux, flux with sawdust. I would flux at least thrice. This is a good time to even throw in a little wax with the sawdust to prolong the flames. That CO is one fine reducing agent.
Fluxed three times with sawdust and twice with a chunk of bullet lube. Still got some weird fish eye looking stuff on the surface that would not go away.
a little antimony or tin bumps the bhn up pretty quickly.
it takes more in the middle teens then tapers off quickly.
1 to 1-1/2% gets you right up there that's why a lot of guy's cut their ww's.
any way I would use your 22 lead to bump ww lead with.
I got about 400 lbs of the stuff years back and just mixed it in with my ww alloy 1 to 3 and it's been a solid performer ever since.
I add nothing to the pot to cast it and it has been super nice at taking heat treatment.