Lee Loader

I was recently given a block of alloy in the form of an aircraft ballast weight. Since it came from a retired AF guy I'm assuming it's "mil-spec". Anyone have any idea what the composition might be? It's harder than straight lead but that about all I can tell.

Make smoke,

What's it taste like?

Sorry, had to. That's the kind of answer you'll get elsewhere.

Based on 40 yr of airplane guy stuff .........
It's likely the bargain cheapest stuff they could buy by the rail car load . If that sounds like a cop out it is sort of . A while back I did a surface balance on a Beech ruddavator . With the weight out in hand it was very poorly cast . They also tend to be very sulfery with lots junk to float off . It runs from pure to wheel weight to 1-16 ,1/20 ,1/40 . Pour a few air cool some , water cool a few . If they have anything but tin in them the A/C will be softer than the W/C .
Look up the pencil test if you don't have another hardness tester . 5-7 bhn will be pure , 8-11 will be the tin/lead , from 12 up you're looking at antimony and/or arsnic in the mix . If it came out of a late war warbird it could even be Linotype . There may even be design called out alloys for load bearing counter weights . The stablator counter balance in the Piper Cherokee is a much harder lead that the surface balances on a Beech anything . Cessna elevator surface weights are probably lino class . Ballast would depend on OM or after market and where on what it's installed . 10# to replace an antenna over the trailing edge of a DC3 is a completely different cat than the same assy in a working AG Wagon or Air Tractor or anything RA Hoover flew from show to show .