Oven Heat-Treating......Just how flexible?

[KYCaster]

Felix: I don't understand what you mean by "speed-up" temp. By slow cooling from 400-450 you'd get a dead soft boolit. I think by annealing the oven treated boolits, you could get most any hardness you want between oven treated and ACWW. Results should be pretty consistant and repeatable.....sounds like it should work, anyway.

I guess I'll just have to try it and see. Just what I need, another project! Oh, well, I've been wanting to try some heat treated boolits in the 35Rem. MG and I just got a RCBS 35-200-FN mold. Looks like its time to do some 'sperimentin'.

Jerry

[Cayoot]

[QUOTE=454PB
The toaster oven I used would hold several hundred .44 caliber boolits easily. I got good at transfering them from the oven into cold water, it took about 5 seconds.
[/QUOTE]

So what was your method of transfering? I'm always worried about bumping and distorting the boolits by dumping them into the water (afraid they will bump into each other or the edge of the pan when I dump them out.

What nuggets of wisdom can you offer on this?

[Bass Ackward]

Bass, what about the 3% Tin content that we have discussed recently. Would I still try to maintain it in this 33% pure lead-WW alloy or forgo it to obtain a softer boolit? This sounds like something I'd like to try.
Brushy

BB,

Same strategy. I just simply refer to WW as a standard. Although you actually change it when you add tin or anything else. So whenever you see me talk about WW, I am refering to a mix that includes some antimony that results in an air cooled hardness of 11-14 BHN. The tin is my aid for a tougher, more ductile hunting bullet.

Today's WW mixes will vary from @ 2-4 percent depending of how many you get from each manufacturer and how much of the pure lead ones get through. I feel pretty comfortable that I will not go over the antimony content of my WWs if I hold tin at 2%. And none of my bullets have ever broken up during expansion testing. This is easy in my mind because all of my WW is free anyway. So tin is a modest expense for me. Could be that I could change that to 1% today. Old habbits ..........

Added: But when you add more pure lead you are diluting the antomony content which makes a more ductile bullet anyway. So you may not need any tin for that purpose. Who knows? You will just have to try it.

[waksupi]

I am also concerned about bullet damage on the transfer. What I do, is pull the little tray from the broiller oven, and immediately drop the tray and bullets directly into a bucket of water. Seems to work OK to me.

[stocker]

As Brush Buster mentioned I use a heavy duty parts washing basket that is made from perforated steel of fairly heavy gauge. It's about 16" diameter and several inches deep. I don't dump the boolits. Basket and boolits go together into the quench. There is enough live steam generated that you must protect your hands, wrists and lower arms and face from scalding. I have removable steel dividers for the basket to segregate different boolits.

[drinks]

Waksupi;
That would be appreciated, I have been threatening to run a test series, but it would take at least 2 days to do it right.
Don

[BABore]

I do my oven heat treating in a couple of nice trays I built out of 1/2" x 6" x 6" aluminum. Put in 52 blind holes with a 1/2" end mill, 1/4" deep. Added a loop handle out of stainless.

I use a standard (Jenair) kitchten oven for my heat treating. With straight WW's I HT at 435 F for 60 minutes then quench in a sinkfull of cold tap water. After a day or two hardness is 28-30 Bhn. I've tried water dropping the WW bullets, but get a bit more inconsistency, like 26-30 Bhn. Larger bullets show a higher variance than the smaller ones. I can understand why you get such a spread when WD bullets because of all of the variables involved.

Lately I have done some research on annealing oven heat treated WW bullets. Starting with OHTWW bullets that were several days old I put them in the oven for 60 minutes, then turned off the heat. They were removed when cold. Working in 25 F increments, I established data points of 15, 18, 21, 23, and 25 Bhn. Temperature ranges were 250 to 325 F. I'm currently working on a larger scale batch for accuracy and penetration tests. Going to be a long project. On one test batch of WDWW's I did find that the hardened bullets going in, with some variation, showed almost zero variation once annealed. Could be a good thing for production speed and to save a step. I don't think annealing would be sucessful in a small toaster oven as they're not as well insulated as a normal oven. The temperature would likely drop too fast for a proper annealing.

I've also played around with alloying WW's with pure lead as recommended by another well known member. The ultimate hardness can be controlled pretty well by varying the Pb amount. A WD or OHT hardness of 18 -24 Bhn can be achieved easily. Expansion and and ductility are also realized with this alloying.

[BrushBuster]

So many great responses to this post that I just have to give thanks. It always comes back to getting busy and try it out yourself, but these contributions do put one on track and save time.

I've already experienced better shooting with CB's than I ever did with jacketed, and been a while since I've been this enthused. I'm hooked!

Joking aside, my missus supports my boolit projects, and as long as I don't abuse kitchen privileges, I should be allright. Something about keeps me out of mischief?
Brushy

[Greg]

What I would like to try is a range of softer boolits, and was wondering what the flexibility of the oven method is? What can I vary? The oven temp. and/or time factor, or the water bath temperature? Anybody fooled around with this before?
Thanks,
BrushBuster

This is my method for heat treating boolits with my alloys and oven. Your results may vary.

Bring the oven up to temperature, then place the sized bullets in the oven, and the set the timer for 1hr Quench in ice water, let steep for 30 minutes. Towel or air dry, then lube. If you notice, the gas check will turn on the boolit base.


Wheel Weights:

Wheel weights SLUMP when heat treated at 485º


Results:

Cast at 680º Heat Treated at 400º for 30minutes for a BHN of @ 12 after 72 hours.

Cast at 680º Heat Treated at 450º for 30minutes for a BHN of @ 14-15 after 72 hours.

Cast at 740º Heat Treated at 465º for 1 hour for a BHN of @ 20-22 after 72 hours.


92 - 6 - 2 Alloy: Magnum shot with 2% tin added...


Results:

Cast at 740º Heat Treated at 400º for 1 hour for a BHN of @ 12-13 after 72 hours.

Cast at 740º Heat Treated at 465º for 30minutes for a BHN of @ 16-17 after 72 hours.

Cast at 740º Heat Treated at 465º for 1 hour for a BHN of @ 21-22 after 72 hours.




50 : 50 Alloy: equal parts by weight of pure lead and wheel weights...

I heated the 50 : 50 alloy to 500º, it never did SLUMP.

Results:

Cast at 740ºand air cooled, for a BHN of @ 6 after 72 hours.

Cast at 740º Heat Treated at 430º for 30minutes for a BHN of @ 15-16 after 72 hours.

Cast at 740º Heat Treated at 465º for 30minutes for a BHN of @ 18-19 after 72 hours.


Remember, these temperatures are for the electric oven that I use. I normally do a smaller batch and quench in a plastic 2 gallon bucket. I add ice to the quench bucket to appease my superstitions. for large batches (seldom) I use a five gallon bucket.

[KYCaster]

BABore: Your tests confirm what I was just guessing at. Saved me a LOT of work, thanks. The only thing that surprised me is the 250-325 temps. I was guessing a little less than half the melting temp. would be required.

Jerry