water quenching

[rmcc]

I have been here awhile but have not really cast that much, still learning (A LOT). I have read that water quenching your WW cast vastly increases the BH of your bullets. My question is how much and does the temper last?

rmcc

[imashooter2]

How much depends on alloy and the temperature differential between the water and the castings. Hardness increases over 24-48 hours and then the castings soften gradually over years.

Not the answers you were seeking, I know. But no one can provide hard answers to a question with so many variables.

[GregLaROCHE]

Imashoter2 is right, there here are a lot of variables involved. I’m sure some members will share their experiences and theories here.
I water quench only because I can get undistorted boolits all the time, casting at a fast pace. When I use the dry method, some always seem to end up with little dents in them, unless I am super careful.

[ioon44]

I did a lot of water quenching years ago and found the hardness will go back to the alloy hardness after a number of years.
A hard bullet will be more prone to leading if it is not sized .002" or more over the barrel da.
For me water quenching was a waste of time, bullet fit is king.

[243winxb]

Q: Is there anything I can do to make the bullets harder?

Cast bullets can be heat treated to increase their hardness providing your alloy has 2% or more antimony present. To heat treat your bullets: Cast your bullets in the normal manner, saving several scrap bullets. Size using RCBS 2 Lube. WASH OFF. Place several scrap bullets on a pan in your oven at 450 degrees and increase the temperature until the bullets start to melt or slump. Be sure to use an accurate oven thermometer and a pan that will not be used again for food. Once the bullets start to melt or slump, back off the temperature about 10 degrees and slide in your first batch of good bullets. Leave these in the oven for 1 hour. Remove the bullets from the oven and plunge them into cool water. Allow them to cool thoroughly. When you are ready to lubricate, install a Lyman sizing die .001" larger than the one used to initially size them, OR Tumble lube with Alox. This will prevent the sides of the bullets from work-softening from contact with the sizing die. Next apply gas checks if required and lubricate. BULLETS WILL TAKE 2 WEEKS TO FULLY HARDEN. These are now ready for loading.

[JonB_in_Glencoe]

a quote from chapter 3.
From Ingot to Target: A Cast Bullet Guide for Handgunners©


Heat treating and water quenching.

This age hardening of antimony containing alloys can be accelerated at higher temperatures, i.e. heat treating the bullets. This is most commonly done by sizing the bullets first (since lead alloys work soften, and hence sizing would negate a significant portion of the hardness imparted by the heat treating process) then heating them to about 450° F in the oven and quenching by dumping them in cold water. The hardened bullets are then lubed using the same sizing die that was used before (so that no actual sizing takes place). Done in this manner, bullets cast with an alloy containing 5% antimony, 0.5% tin and 0.17% arsenic, which would normally have a Brinnell hardness of a little over 16 (after aging for 6 days), can be hardened to a BHN of over 35 (see Dennis Marshall‘s chapter “Stronger Bullets with Less Alloying“ in “Cast Bullets” published by the NRA). Notice that this alloy is not tremendously different from the common wheelweight. Much the same sort of result can be obtained by casting with a hot mould and water quenching directly (place a towel over the water bucket with a 4“ slot cut in it to contain the splashes). Mould temperature is critical for maximum effective hardness. Bullets water quenched from a “cool” mould (i.e. one from which the bullets were smooth and shiny) were found to be similar to air-cooled bullets. But bullets dropped from a mould that was “hot” (i.e. hot enough that the bullets were frosty over their entire surface) were found to have BHN of over 30 when water quenched. In a separate study, such a mould was found to have temperature of 430° F, very similar to the optimum oven temperature found in the heat treatment study (ca. 450° F). I don’t normally cast quite this hot, but even so, water-quenching WW alloy routinely gives me bullets with a Brinnell hardness of 18. One of the advantages of hardening bullets in this manner, as opposed to using linotype to make them hard, is that they are tougher and not as likely to shear or fragment on impact.

http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.ht m

[JonB_in_Glencoe]

How long?

I used 94-3-3 in a heat treat experiment (243 caliber bullets).
I was told by others that tin content over 1/2% will age soften faster then a similar alloy with less than 1/2%.
My tests went out 2 years. The 94-3-3 hardened to 24BHN. After two years of aging, BHN measured 22.
FYI, my 94-3-3 typically is 14 to 15 BHN air cooled.

[rmcc]

Thanks guys!! I have a lot to learn!!

[Larry Gibson]

How long?

I used 94-3-3 in a heat treat experiment (243 caliber bullets).
I was told by others that tin content over 1/2% will age soften faster then a similar alloy with less than 1/2%.
My tests went out 2 years. The 94-3-3 hardened to 24BHN. After two years of aging, BHN measured 22.
FYI, my 94-3-3 typically is 14 to 15 BHN air cooled.

What JonB said.

[Winger Ed.]

Years ago, hardening was the craze--- like molly coating was, powder coating is now.:bigsmyl2:

Everybody was all scientific about exactly what temps. you needed to do it right, and on and on.
You HAD to put one on a tray in your oven, keep raising the temp. until it 'slumped'.
Back the temp. off a little, and cook your boolits a certain length of time, then take 'em out
and dump them into a bucket of water.

I don't push my boolits very fast, not much over the mid-teens, and really don't need to harden them at all.
I mix together my mystery alloy with pure Lead, and enough
wheel weights and/or all the discarded samples my buddy at the old Dallas Lead plant used to bring me.
If it flows well, and I get good fill out--- I call it good.

So some of us figured out, you got to the same place by dropping boolits out of the mold into a bucket
of water safely away from the pot, and with a towel or different things floating on top to hold down the splash.
I'm not worried or stressed out over how hard they are, it's just convenient, and I don't get dented boolits.

[Budzilla 19]

Cast rifle bullets out of 50/50 ww/pure with 2% tin, air cooled, gas check is installed, powder coat, heat treat for 1 hour @425F,while curing powder coat, splash in ice water. Size to .310” for 30 caliber. They perform great!
Might be doing it wrong, but it seems to work ok for me. Your mileage may vary. Good luck.

[Geezer in NH]

Worried about hardness over years??? Who has them for over years even months? Mine get shot way before that problem. Not being shot they will get melted and remolded to what I am shooting,

[imashooter2]

I often cast several thousands for something that falls out of favor. They can sit for years before I pull the platform out of the safe again and rediscover why I bought it. Since I have plenty of alloy, I see no point at all in melting good boolits into something else.

All that said, I don’t worry about quenched boolits going soft either.