UN-heat treating a boolit?

[Bigslug]

One of those little bits of the learning curve - dad and I got into casting a few years back, and water-dropping boolits was just how we assumed it was done. For the rifles that we were casting almost exclusively for, this worked fine, but now that the low-velocity handguns are coming into play, we've come to understand that the answer there is "not always".

I'm dealing with a range scrap alloy with some wheelweights thrown in, the ingots of which tested at 9.75 BHN and the water-dropped boolits from which test at about 14. The jury's still out on how hard my .45ACP slugs need to be, but I think it's a safe assumption my as-yet untested .38S&W projectiles need to be on the softer end. Thing is, I've got about 700 of them that were water-dropped, and would prefer not to re-melt if at all possible.

My question then - Is there a critical temperature, short of reverting to a liquid, that I can bring these up to, then allow to slowly cool back down to a softer state?

[5Shot]

If you re-heat them in a heat treat oven and then let them air cool they should be soft again. You can google "Heat Treating Cast Bullets" to get the temp. I think anything close should work. Just leave them in there for 60 min.

According to the chart that accompanies an article by Rick Kelter, anything around 480 should work (but not over). Lead melts about 100 degrees hotter than that, so you shouldn't lose any.

[kelbro]

Test them. Depending on how long ago that they were water-dropped, they may have lost some of their hardness.

[fecmech]

Why not shoot them hard and see what happens before you make work? I shoot WDWW bullets in my K-38 and I see no difference in accuracy or leading from ACWW bullets.

[imashooter2]

Why not shoot them hard and see what happens before you make work? I shoot WDWW bullets in my K-38 and I see no difference in accuracy or leading from ACWW bullets.

Solid advice there.

That said, I had several hundred castings that I returned to soft by heating them in a toaster oven to 425 degrees for half an hour then turning off the oven and letting them cool inside it. Worked like a charm.

[Defcon-One]

I agree with the last two post:

1.) Why not just shoot them? Then just don't water drop from now on.

2.) It really all depends on alloy content. I'd try 425 to 450 degrees F for 30 minutes. They will be up to temp by then and they won't get any hotter if you wait longer. (You'll just waste electricity.) Then gently remove them from the oven and let them cool slowly or just turn it off and leave them in it, like he did. Over 450 and the Tin can melt and bubble out causing bumps and irregular surface blisters. At much over 480 you may get some slumping, something that you don't want. Also, if you are using your home oven, preheat it and remember that the thermostats are typically good for plus or minus 10-20 degrees F. (A setting of 450 may get you 470 or 430!) I'd use a digital kitchen thermometer to check it, if you have one.

Good luck!

[Bigslug]

Oh, for a certainty I'll shoot a few as-is first. Just needed to make sure that the water-quench "pencil" had an "eraser".

[runfiverun]

and you don't need to get them that hot, they weren't that hot when water dropped.
and you'll most likely slump all of them at anything over 400.

[Bigslug]

Well. . .my little Harbor Frieght laser indicates most mold blocks are at about 350 degrees when they're dropping pretty boolits. Would that be a good place to set the oven?