Annealing....

[Lefty SRH]

I water dropped some .480 boolits and they are running about 20BHN. I don't want to melt and recast them because my sizer is broken at the moment. Is there a way to anneal these boolits down to a softer BHN?

[truckboss]

Put them in the oven bout 450 for about 1 hour,let them air cool. Your oven's temp might vary so try 1 boolit for a while to make sure it doesn't slump,then put the rest in.

[Lefty SRH]

Do you pull the boolit out of the oven to cool?

[cbrick]

Do you pull the boolit out of the oven to cool?

No need, just turn the oven off, open the door and let them sit there until room temp. At 450 degrees it's gonna bring them back to as cast, air cooled BHN.

Rick

[44man]

No need for softer in the .480 anyway, it is deadly with hard and will turn deer inside out with zero expansion.
My boolits run 20 to 22 BHN after water dropping and that is what I hunt with.
The .480 is as good as you can get so I would only look for accuracy and test different hardness only for that purpose.
20 BHN might just be super.

[Lefty SRH]

I can't give you an exact BHN # but I did some boolits (20) in the oven last night for 1 hour and turned the oven off. I let the boolits sit in the oven til it was completely cool. I can now push a finger nail into the boolit. I can't even get my nail to grab the other boolits that were not annealed.
Thanks for the tips.
Next thing is to take some air cooled boolits and see if I can harden them by warming to 450-ish and them dropping the into water.

[cbrick]

Next thing is to take some air cooled boolits and see if I can harden them by warming to 450-ish and them dropping the into water.

IF there is antimony (Sb) in the alloy they will harden. If there is arsenic in the alloy (WW) the effect will be more dramatic. There is an age hardening time curve, don't expect them to be hard when you take them from the water, at this point they are still quite soft.

The percentage of Sb will determine the time curve. The higher the percentage the more quickly they will harden. Even so there is still an age harden time curve, 3+ days or so. A lower percentage of Sb and it could be a couple of weeks but they will still harden.

Rick

[runfiverun]

i'd try a couple before going all the way to 450 with them all, you can get some extremely hard boolits by oven treating.

[blackthorn]

Normally, we do not think in terms of ‘annealing’ lead; however there will be times when you want to adjust the BHN of your bullets to suit a specific purpose. If you want something between 11 BHN (normal for ACWW) and 30 BHN, and prefer to stick to using WW alloy, then water drop your bullets and ‘draw’ (temper) the alloy back to whatever BHN you need. The final hardness will be a combined result of temperature and timing. After they are drawn, they can either be air-cooled or quenched in cold water on removal from the oven. Here is a chart (you may have to adjust this chart for your alloy) that can be used to ‘draw’ your bullets:

Draw Temperature Time BHN
200 1.25 hrs. 26
225 0.75 20
225 1.5 18
237 0.75 18
250 1.5 15
263 1.0 16.5
275 0.75 14.5
288 0.175 12.5

The above chart is an approximation using bullets that have been water-dropped from the mould, heat soaked in an oven and then quickly quenched in ice cold water. The BHN of any specific alloy will depend on its constituent makeup so it may fall between, above or below the chart BHN and you will have to adjust the timing based on what your hardness tests indicate.

Quenching into a bucket of water straight from the mould works well to harden your bullets, but it is impossible to produce absolutely consistent bullet to bullet hardness simply because of the external/human factors, i.e.; casting rhythm, fluctuation of mould block temperature, mould block temp/alloy temperature ratio, material of blocks etc. The point is, ‘drawing’ will bring all of your bullets back to the same temper as long as the bullets are already harder than the target BHN.
There you go---have fun!

[PacMan]

A little diffrent take on things.
I put WD WW in a toster oven for 1 hr. at 350 deg. and then remove and let cool at room temp. which gives me about 12-13 bhn.

The problem with annealing is if you are using WW and soften much below ACWW hardness they will change in a couple of weeks. If you heat them to high for to long then let them cool in the oven they will be fairly soft but in a couple weeks they will be around 12-14.

My experience only.