Heat Treat Fiasco

[Stonecrusher]

A lesson learned the hard way is best remembered. I have been messing with homemade gaschecks using .02" aluminum. I had originally made these to use in my Mosin sized to .3165" and decided to see if they would work with my .30-06 sized to .310". I was getting a little nose distortion when sizing in my 450 because of the thickness of the check. The base of the check was also a little convex. I guess the material has to go somewhere.

To correct, I bought a .309" Lee push through die and honed it to .310". Problem solved! Perfect looking bullets and the base is nice and flat. Of course, I can't leave well enough alone. For no good reason, I figured I would heat treat a few and see how they worked.

I was using coww w/2% tin and I put them in the oven at 450 degrees for one hour. Having never heat treated any boolits before I laid them flat on a cookie sheet:oops:. After an hour I dumped them into a bucket of water. They were harder! Great. I noticed a tiny flat spot on all boolits where they laid on the cookie sheet. It was less than .010" wide so I figured most would size out and the rest might not matter very much after going through the rifling.

I installed checks, sized and lubed. Yes I know, should have put checks on first. Everything was looking good.

This am I started dropping powder and seating boolits. First one looked visibly crooked after seating. I thought, huh? Never had that problem before. Dug out indicator and v-block and checked. Running out about .015" near the tip. Only thing that changed in my loading procedure was that I was trying out a new Lee collet neck size die. Being a Lee hater, that had to be it, right? I full length sized one with my RCBS die and expanded and seated, It was no better. By now I was pulling my hair a little.

I dug out some 7.62x54 I had loaded with some 316299's and they were only running out about .001"-.002" at the tip. Well, my equipment seems good.

I tried a few acww boolits and they seated straight about same as the 7.62x54. Hmmmmmm.

Then I got a good look at the heat treated boolits. Apparently 450 degrees is a little too close to the slush point of that alloy and all the noses slumped to the side. The picture below shows the damage. Fortunately I only ruined 40 boolits that I have to pull to remelt.:shock:

So, if you are as ignorant as I was about heat treating, don't lay boolits on their side and maybe use 425 degrees instead of 450. I don't know where my brain was when I did this. Lesson learned and I don't think I will forget.:bigsmyl2: And it only cost me half my hair and a couple hours of my life that I can't get back.

124025

[Calamity Jake]

I HT everything at 425° never had a problem with slump.

[paul h]

You missed the opportunity to shoot them for groups to quantify how well lead bananas fly ;)

I'm pretty sure all of us who have been at this for a stretch of time have managed to make a mess of things at least once.

[Maven]

"So, if you are as ignorant as I was about heat treating, don't lay boolits on their side and maybe use 425 degrees instead of 450. I don't know where my brain was when I did this. Lesson learned and I don't think I will forget." ...Stonecrusher

Stonecrusher, I had that happen to me as well, but it wasn't because the CB's were horizontal and stacked two deep no less. Rather, it was because I didn't monitor the oven's temp. carefully enough and they essentially began melting. Other than reducing the temp. to 425 as you suggest, you may want to add a 12" x 18" sheet of Al foil to your oven to help even out hot spots. (This worked for me in an electric range/oven, but not the current computer controlled gas one:? we present own.) Another suggestion is to make a basket of hardware cloth + a bail, i.e., very coarse screening with the "squares"/grid ~1/4" apart. Stack the CB's 2 deep and then quickly submerge the entire thing into cold water. Btw, some use the round basket from an old percolator for this purpose, which works just as well, but you can keep the CB's vertical if you prefer. Lastly, not a suggestion, but a question: Do you need to heat treat your CB's? Once I discovered our present oven wasn't reliable enough for HT-ing, I stopped doing it and found I got no more leading and no less accuracy with gas checked CB's in any of my rifles, which includes a .30-06 and a Finn. Nagant.

[Yodogsandman]

I bought a cheap oven thermometer from wallyworld for $6. I found that the actual temperature of my convection/toaster oven was 50F higher. I just set it at 400F, now. BTW, I always lay them down in a single layer and quench the whole tray at once. I like to use ice in the water unless I have to break the ice in winter to quench.

[Stonecrusher]

Maven, No I don't need to heat treat. I just figured to give a try and see how it worked. I noticed that some older 31141's out of almost pure lino I had seemed to shoot a little better than the current crop and that is why I was giving it a shot. I think the biggest problem was the top punch causing distortion when sizing the larger checks. The nose first sizing seems to have corrected this problem. I think they will shoot much mo better now.

[catskinner]

I have melted bullets in the heat treating process. Now I check oven temperature by starting with a few reject bullets to make sure I don't melt my good bullets,

[geargnasher]

You're in the "club" now. My lesson was never trust what the digital temperature reading on the cheap-line GE oven SAYS the temperature is....verify! Also, don't put your casting thermometer in the oven, particularly if the crystal isn't crystal....

Gear

[dragon813gt]

Maybe it's just me. But I'd want to shoot them just to see how they do.

[RED333]

Great thread, thanks for the experience!!!

[Stonecrusher]

Maybe it's just me. But I'd want to shoot them just to see how they do.

I thought about doing that, but don't want to waste what little 2400 I have left. Would you like me to send you my pulls?:kidding:

[dragon813gt]

I thought about doing that, but don't want to waste what little 2400 I have left. Would you like me to send you my pulls?:kidding:

Doesn't mean you have to use that powder. A few grains of fast pistol powder at a short distance would do :)

[popper]

I've gone to 420F but I don't use any tin. I'd stay closer to 400-410F if using tin, lowers the slump temp. The barrel should straighten them - right? :killingpc

[Stonecrusher]

Doesn't mean you have to use that powder. A few grains of fast pistol powder at a short distance would do :)

You have a point. Might try a group or two just for giggles.

[243winxb]

See Lymans FAQ for heat treat info on there website.

[Stonecrusher]

See Lymans FAQ for heat treat info on there website.

Thanks for the tip, I never looked at Lyman's FAQ. My original post was more of a "What Not To Do".

[rintinglen]

I heat treat to 450 on my oven--which is actually about 435 on the meat thermometer. However, I used the technique written up by Dennis Marshall in either the Lyman CBH #3 or the RCBS #4, ( I can't remember which and don't feel up to getting dressed right now). Assuming a Pb, Sn, Sb alloy, (Not pure lead or Pb-Sn), Take some reject boolits, set them standing up on a metal, oven-safe tray, and place them in the oven at an indicated 420 degrees. Let them bake at 420 degrees for 45 minutes, remove the tray and carefully examine them. Put 'em back in and raise the temp 10 degrees, and try again. Somewhere you will start to melt the boolits. Stop. Lower the temp 10 degrees and try again with similar boolits. Heat them and remove them several times. If no melting or slump occurs, then you have found your sweet spot for that alloy.

Make a hardware wire tray about 4 inches square don't forget to make a handle. Lay your good boolits, sized and gas checked but not lubed, on their sides in close packed rows. Do not let them roll around while hot. Put them in the oven for 45 minutes at the temperature you have determined to be your sweet spot, take them out and plunge them into a bucket of cold water. BHN of 25-30, depending on alloy.
For a time, I heat treated all my boolits, but found no advantage to heat treating boolits that would be shot at velocities under about 1300 fps, save for 9mm. For some reason. my old S&W M-39 leads a whole lot less with hard boolits of proper size. Even at relatively low velocities. There are darned few rules in casting that somebody's gun won't break.

[Stonecrusher]

Thanks for the tips Rintinglen. I don't have much, if any, need for heat treat but may in future. I've survived thirty years of this without a need yet.

One good thing, my Al checks stayed firmly on while being pulled. I was a little concerned since the 31141 had the check just below the shoulder.