Need to "soften" cast boolits! What to do?

[10 ga]

I'm a ML kinda guy. I even have some ML "safe queens". Have been gifted a quantity of cast boolits and since I will be shooting them in sabots I'd like to "soften" them up. They are about 20 BHN now and like to get that down some, in the 10 to 15 range or softer. I was told to stand them in a cookie pan with about 1/4" of water and use a proane soldering torch on the tips to soften the front of the boolit. Will that work or am I into a try it and test it kinda mode? These are obviously for hunting (whitetail) and I like to get some expansion. They are "44" cal., really .4301 and are 230 gr. wt. This cal boolit shoots good in most of my MLs where I use sabots and I'd rather use them than smeltem. I traded off my Marlin lever in .44 mag so don't have a cartridge sorta use for them. If they were .50s I wouldn't worry just PP them and shoot them as .50 is plenty big w/o expansion. Advice, experiences and ideas welcome. Thanks all, 10 ga

[dverna]

How would that soften the bullet?

Me thinks you will be melting them and adding lead to the mix.

Don Verna

[Harter66]

I believe the question was "can I anneal these boolits?". If they are for example WDWW I think they can be annealed. I've seen in here that heat treating is done by oven heating to 400* for an hour and water cooling .it seems to me if the boolits were heated the same way and air cooled you would get the opposite effect and get around a 14BHN. I have been wrong before , could be in this too. It might be easier to swap those boolits for metal or soft boolits.

[helg]

There may be a way to soften the cast bullets.

If the bullets have been heat-treated or water quenched to that hardness, they can be annealed to lower down the BHN.

Lead alloy is like steel. It becomes harder, when being cooled quickly, and softer when cooled gradually. Heating the bullets almost to melting temperature in an oven, and then gradually reducing the oven temperature to the room one within 10-15 minutes, or slower, should anneal the bullets, and make them softer.

Again, this only applies if the bullets have been quickly cooled, e.g. heat-treated or water-quenched. The bullets may have been bade from high arsenic linotype alloy, and gain the hardness without heat treatment. In this case the annealing does not help. Bullets from wheel weights have BHN around 13 air cooled, and around 20 when water quenched. Annealing WW bullets with BHN 20 will lower the BHN.

I have not done this myself, though I am positive that the annealing should work this way with WWs.

[theperfessor]

Most metals are softened by annealing, which requires heating of the metal above a "critical temperature" which is the temperature that marks a "phase change" from one type of microstructure to a different microstructure. Most metals require slow cooling from that temperature to allow time for the softest microstructure to form; quick cooling such as a water quench allows a harder microstructure to form. (Brass seems to be the exception here as the cooling rate doesn't really make any difference.)

I would put them in oven at 425-450 and after they got up to temperature I'd wait a few minutes and then shut off oven while leaving bullets inside. When all cools off to room temp I bet they'll be as soft as they'll ever get.

This would affect whole bullet; using a torch might soften tip but might be harder to do consistently without a lot of practice.

[felix]

Typical demarcation temp is 300F. Leave in oven for one hour, and shut off oven with door closed all night. ... felix

[JeffinNZ]

Tell them it's not safe to climb trees, walk to school on your own and that winning doesn't matter, it's about taking part. That has made our younger generations in NZ soft. Has to work for bullets.

;-)

[stubert]

How about the Forster tool to hollow point them? about $25.00. Expansion problem solved.

[Larry Gibson]

If the BHN is 20 based on these cast bullets air cooling in the 1st place then that hardness is based in the alloy mix. So would heating them and simply letting them air cool again really lower the BHN? We know it will if the bullets are WQ'd or oven heat treated but will it if they are already AC'd and at 20 BHN? I do not know the answer.

Larry Gibson

[runfiverun]

it would be a very short term temporary fix.

if they are 20 bhn. id just get someone to swap you what you got [alloy]
for what you want. some 50-50 ww' /pure air cooled, or even 50-1 pure/ tin would be a much better long term alloy.
unless you only need one boolit.

[theperfessor]

Doubt that they would soften much if they are that hard after air cooling. They probably would soften some if they were originally water quenched. That's reason I included tag line in my first post of "When all cools off to room temp I bet they'll be as soft as they'll ever get." And that may not be any softer. But it might be worth a try and it won't hurt anything except melt some lube off, and if they will be shot in a sabot that shouldn't matter except for the smell, might want to de-lube them first in boiling water.

[303Guy]

If I may add; I've only played around a little with alloys (and got terribly perplexed in the process). I have an alloy which air hardens but it was cast from a previously soft alloy. I've also attempted to harden and anneal an alloy and found that it can go the other way. Solution heat teating is what you get if the alloy is just right and the temperature of the oven is just right, meaning the boolits harden instead of softening! Then I had an alloy that would produce a two-hardness boolit out the mould with slow cooling! The softer nose was frosted while the base shank shiney - the base portion of the mould allowed faster cooling by design but for a different purpose.

Try some in the oven and see what happens. They migh anneal just nicely and regain their hardness in an hour or two. (My crazy alloy could be hardness plotted over time in just two hours! The difference every 20 mins or so was astounding. At first I thought I had made a measurement error until I tried it again with the next casting). All fun!

[mroliver77]

If these boolits happen to have a nice big meplat I would not worry about softening them. 100gr bp behind that .50 sabot should move them way past 2000fps if my memory of loading the sabots is correct. A Keith boolit hitting a deer at 1600+fps will leave a gaping hole with no boolit expansion.
I shot a deer with a light loaded 45-70 with the Lee 325gr boolit with a small meplat. I estimate it was traveling 1200fps. I was within 40 yard of it so boolit didnt slow much. Nice 3/4 -1" hole through the boiler room and deer ran a short ways and died withing 15 seconds.
Jay

[Cowboy T]

IF that lead is actually Linotype....

The only way I can think of is to not use them in the muzzleloaders. Here's why. Linotype doesn't get its hardness from heat-treating. Air-cooled, it is naturally BHN 21 or so, so it's already been "annealed" simply through the casting and cooling process.

The only way annealing will work is if the lead got that hardness from heat-treating in the first place. That would mean it's wheel weight lead or something similar.