Terry - good topic. Water quenching will only harden lead that has both Antimony AND Arsenic in it's composition.
The old lead wheel weights with crimp-on attachment clips, as well as 'hard' lead bird shot, contains both enough
antimony and arsenic to cause water hardening if bullets or balls made from them are quenched.
The hardness progresses from still relatively soft at the quench, over the next 12 hours or so, where it becomes the hardest
it will become. Then over a period of time, the then-hard lead softens to the point, were over about 2 or 3 years, it will
again become the same Brinel it would have been without being quenched.
Many of us made & used HARD bullets with quenching from the mould or using an oven, then quenching the bullets.
Using an oven where the lead was heated to within 10 F of slumping, then quenched in cold or even room temp water,
would, after 12 hours or so, become up to 34 brinel in hardness. This was starting with lead at about 12 or 13 brinel.
Quenching out of the mould, will give a variety of hardness, due to the rapid cooling & this different temperature of the bullets
or balls hitting the water. Thus dropping into water through a slit in a towel over the bucket, from the mould will deliver hardness
from about 25 brinel to 32 or so. Much depends on the actual temp of the lead hitting the water. There needs to be a towel in the
bottom of the bucket as well as the bullets or balls will still be somewhat soft and banging together is not good for them. The towel
in the bottom softens the blows.
Bird shot, if cast into bullets, due to it being lower in antimony content, will not attain the hardness of the old WW. WW seem to rule
in making hard bullets. They become hard, yet ductile when meeting bones, whereas Linotype alloy shatters.
In order to harden, the mixture MUST have the requisite arsenic. Pure lead is 5 brinel. Water quenching pure lead will do nothing.
Lynotype, if old, is usually around 20/21 brinel. That is very hard to start with, but quenching is unlikely to make it any harder due to
the lack of arsenic in it's composition. The addition of some WW or lead shot to get the arsenic content up to, I think, .03%???, although will
soften the antimony as-is, but will provide enough arsenic to harden these up to 34 brinel, which is the hardest that can happen with this process
and happens with oven heated then quenched WW, which are brinel 12-13 to start with. Seems to me, the US wheel weights ran 9 to 12 brinel. It's
been a while since I was involved in this stuff.
For comparison, dead soft copper, is 35 brinel. To be able to make bullets from WW and attain almost that hardness, is quite incredible. All this is covered
in detail, in Veral Smith's book "Jacketed Performance from Cast Bullets", a book I bought back in 1977/8.
The cool thing about hardened bullets by this process, is they do not become brittle, as-is straight Linotype. I suspect the slightly harder Monotype (24 brinel)
is similar in brittleness to Linotype.
