heat treating question

[ian45662]

When you heat treat a boolit or water quench a boolit how much of an affect does sizing have on a heat treated boolit?

[AZ-Stew]

Size and seat GC before heat treating. Then it makes NO difference. Lube later using a .001 larger die.

Regards,

Stew

[captain-03]

Size and seat GC before heat treating. Then it makes NO difference. Lube later using a .001 larger die.

Regards,

Stew

That is exactly how I do it ... works well ..

[sqlbullet]

IMHO, none.

Every hardness tester I have seen does so by an indentation. The depth of the indentation is orders of magnitude greater than the .0005" to .001" you will affect the projectile when sizing.

If this single disturbance of the metal had a significant impact on hardness, a different test would have been devised and implemented by engineers.

If you are concerned, by all means, heat treat after sizing and lube on a die .001" larger than your size die.

[lurch]

It takes some time for the hardness to increase after quenching or water dropping. Anywhere from a day to a week or so depending on many things: how hot the initial temperature was, what the alloy is, what the storage conditions are after the quench, the phase of the moon and the temperature of the sidewalk. Sizing right after quenching is your best bet if you need to reduce the diameter of your castings for your application. If you just want to stick lube in the grooves without knocking down the size, you can do that anytime with a larger die as mentioned.

The effect of actually sizing the boolit after hardening has happened is to soften the boolit. Now is when we open that can of worms... How deep does the softening go (or for that matter, how deep is and what is the hardness profile as you go from the outside of the boolit inwards)? Is the softening deep enough to affect results and how much? There are probably as many opinions as there are navels on this board. Personally I'll just size as soon as I quench. That way I know what I am doing is repeatable. Also, I have seen no need to worry about pistol bullets. ACWW seems plenty hard for what I want to do with them. The '06 on the other hand likes them a little harder than that.

[Marlin Junky]

I size and check within a day of heat treating. If you heat treating gas checked boolits, the checks (annealed or otherwise) will loosen. The last batch I heat treated had an air cooled hardness of BHN 10. After a 1 hour heat treat at 485F, a quench into ice water and about 10 days of aging, the boolits registered BHN 30 on my Lee hardness tester... which is too hard for sizing in a Lyman 450. This particular alloy was made of commercial pistol boolit range scrap (good source of Sb which really drives up the HT'd hardness), COWW metal and Pb.

MJ

[reloader28]

I size mine immediately after heat treating. For me, its 475 degrees for one hour. About one hour after heat treating, they are hard to run thru the sizer, so I only do 100 at a time and that gives me enough time to do them before the bullets are too hard.

Basically to full hardness the next day. I dont remember the numbers, but they are 3/4 or more to hardness one hour.

I also had the problem of loose gas checks when I did that before heat treating.