Heat treating success.

[JeffinNZ]

Hi team.

I have been playing with heat treating lead alloy for some time but only at either end of the scale. IE: as cast or HARD. I have treated clip on wheel weight alloy up to 33 BHN with very good target success.

Over the weekend I had a crack at what I shall refer to as 'partial' heat treating and after a bit of trial and error managed to get my clip on wheel weight alloy with approx 2% babbitt metal to 16 BHN; basically duplicating Lyman No.2. Cooked the bullets (.31 cal for .303 Brit) for an hour at 430F.

Took a bit of playing around with my bench top oven but by slowly increasing the temp increments, quenching, WAITING for the mandatory periods, I got there.

The 16 BHN is after 24 hours so it may even go 17 BHN. I hope this is going to work for me with some current loads where the 'as cast' WW alloy appears to be border line on tensile strength.

Just thought I would share.

[waksupi]

Jeff, I have done a bit of this. I set the oven at 25 degree temp changes, and treated different batches of bullets. I ended up with a very nice range of hardness.

[randyrat]

How long does heat treating last and is there anyway to keep em that way or to prolong the inevitable.

[454PB]

You should see a much harder reading in a few weeks, I would expect upwards of 26 BHN.

They will eventually resoften at room temperature, but it takes several years if they are not sized, or were sized before heat treating.

Some recommend keeping them in a freezer to prevent resoftening, but I never thought it was worth the hassle and haven't tried it.

[JeffinNZ]

Measured again after 48 hours and look to have topped out at BHN16.5 which is pretty much exactly what I wanted. Now to see what the rifles think.