alloy help!

[gofastman]

I have about 100lbs of wheel weights, mostly stick-on's

How much tin and antimony should I add to get a tough, non brittle bullet with a BHN in the high teens to low 20's?

Id like to get as universal of an alloy as possible, I'm casting for .44 now and am going to be adding 10/.40 and .380, And I
push them hard.

I can heat treat them if needed.

I just ordered 12lbs of this:
http://www.rotometals.com/product-p/...ny_70_lead.htm

and 4lbs of this:
http://www.rotometals.com/product-p/..._babbittsp.htm

I also have 2lbs of linotype.

[alfloyd]

If I did the ratios right in my alloy calcaulator, and you mix them ALL togeather, you will have about:

118 lbs of alloy with
Lead ------- 93.4% BHN of 8.5
Tin --------- 3.0% BHN of 30
Antimony --- 3.6% BHN of 30

And a BHN of about 12.5.

Maybe a little harder with the copper added in the babbet.

This will work great for the 44 mag, and can water dropped to increase the hardness.

Lafaun

[buyobuyo]

The alloy I cast with is 50/50 WW/pure with extra tin added. It should be around 1.5-2% tin and antimony. After aging for 2 weeks it comes out to 8.5 BHN air cooled and 20 BHN water dropped.

[leadman]

The website for lasc on the bottom of this page has very good info on mixing your own alloys.

[bumpo628]

By mixing it all together, I got the following:
118 lbs of an alloy with 3.2% tin, 3.5% antimony, 0.1% copper, and @ 93% lead.
The hardness should be between 12 to 13 Brinell.

The tin looks a little high, so you could always add some pure lead to make it go a bit farther. However, it would work for just about anything as is. It would be kind of like a poor-man's Lyman #2.

If you want to play around with alloy mixing, follow the link in my sig for a copy of my alloy calculator.

[gofastman]

If you want to play around with alloy mixing, follow the link in my sig for a copy of my alloy calculator.

This is a wonderful tool! thanks a lot.

does heat treating cause bullets to become brittle?

This will work great for the 44 mag, and can water dropped to increase the hardness.

I have a convection toaster oven that happens to have near-perfect temp control.
I would prefer to use this heat treating method rather than water-dropping if it will accomplish the same thing. will it?

[buyobuyo]

Heat treating shouldn't significantly increase brittleness. The tin content provides malleability to the bullet even after heat treating.

Oven heat treating and water dropping will accomplish the same thing. An advantage of oven heat treating is that you have better control over the final hardness based on what temperature you heat the bullets at.

[gofastman]

is there a chart for temp/hardness when heat treating

[MBTcustom]

Hey there gofastman, I keep reading your posts and you mention hardness over and over. I just wanted to mention to you that it is well known here on the site that hardness is the last thing that should be considered when pushing boolits to fast speeds. The hardness of your boolits performs only one function, and that is to keep the boolit from stripping the rifling on its way out of the barrel.
You can see in this picture how the rifling almost came full circle on this boolit.

That boolit was pushed at 2200 FPS and still made it out of a full length barrel without stripping the rifling. The alloy was 96/2/2 dropped on a wet towel and thats it.
The hardest boolit in the world will never be as hard as a copper jacket bullet. So the main thing to consider when pushing a boolit fast is the gas seal that it has on the barrel, followed by choice of boolit lube and finally as an afterthought, the hardness of the alloy. Its a different way of thinking. Like blowing spit wads through a straw, the tension of the projectile in the pipe makes all the difference in the world.
The most important thing to do when casting for any firearm is to slug the barrel and make sure that your boolits are bigger than the groove diameter by 1-2 thousandths of an inch. If you are shooting a revolver, remember that the boolits will leave the cylinder no bigger than the throat diameter of each chamber, so if you have a .357 magnum and the barrel slugs at .3579 and the cylinder throats measure .3570 you will deal with unstoppable leading no matter how big or hard your boolits are. That's just a fact.
Now 2000FPS is blazin fast for any of the calibers you mention. You should be able to push a PB boolit to 1500 FPS with plain WW alloy in any caliber. You might want to add some tin when pushing that fast. Past that, use a GC design on the 44mag and you wont have any trouble at all with plain 'ol WW alloy.
Hope this helps.

[fredj338]

You really don't need a BHN alloy of 20 for most shooting, certainly not for the calibers you are casting for. Get 50# of linotype & mix it w/ the 100# of pure lead stickies for a very good all around alloy. Water dorp that if you want a surface harder for higher pressure rounds (above 35Kpsi). Your 380 will happily run on an even softer alloy. I shoot clip ww equiv in my 44mags to as hot as anyone would want to shoot them & that is about 13BHN.

[41mag]

I'm pretty new to casting with only about a year under my belt, but thought I would toss this out to you.

When I got started, my goal was to pour up hunting boolits to feed the appetite of my Raging Bull in 454. With the 8 3/8" barrel. Most data for this round is showing loads above 1500fps, and I had serious considerations about leading in the thing, and DIDN'T EVEN want to go there.

I had purchased a couple of Lee molds and had about 3/4 of a 5gal bucket of WW and went into production. After quite a bit of trial and error, mostly error, I managed to start getting great looking boolits and decided it was time to put them into action. As mentioned with a 454, most of the data is for high velocity and even with using Heavy Colt loads, the longer barrel will still bump them up there a bit. My first loads with these boolits topped 1500fps, and the only leading I found was some slight smears in one or two grooves. This was quickly corrected by using the advice of RobS who pointed out to swab the barrel after a good cleaning with a patch coated with LLA. Granted this is a GC designed boolit, but I have also use the 255gr RF up to over 1300fps in the same revolver, with no major issues. It however simply doesn't shoot nearly as well as the 300gr does. The only two lubes I have used were the 45/45/10 mix of ALox, and Felix lube on around 50 test rounds. Since my initial testing I have simple stuck with TL'ing the Alox mix and not had any issues.

Since following this advice I have seen no leading other than what, from everything I have read, should be normal. I can easily run 50 rounds through it with only minor build up and I firmly believe that it is mostly lube and carbon. Certainly nothing I would personally consider as leading. I do get a few, minor specks here and there of lead but nothing that won't come out using the standard wire bristle brush and elbow grease in a normal cleaning routine.

So just to throw this out to you, before you go blending up a bunch of high dollar mix, simply because, I would not hesitate to give the standard WW alloy a good going over in your choices of boolits. After that if you have issues you might bump up the hardness, but I would still give it a thorough wringing out. My alloy when checked on a Cabintree tester is hitting right in the 11 - 13 range on the aged stuff, and around 10 on the week old stuff. I highly doubt that if your fit is good to your bore and cylinders you will have any issues with the standard WW alloy unless your REALLY pushing the pressures on your loads.

I have, since beginning casting, purchased a Redhawk in 45 Colt with the 7.5" barrel. Using the Lee 255gr RF mold my boolits drop at .260grs. This is a simple flat based design, using the same alloy, and tumble lubing with Alox, and I have also bumped them up in this one to just over 1200fps with no issues what so ever on leading either.

Just some thoughts from my experience so far.

[FirstBrit]

I have about 100lbs of wheel weights, mostly stick-on's

How much tin and antimony should I add to get a tough, non brittle bullet with a BHN in the high teens to low 20's?

Id like to get as universal of an alloy as possible, I'm casting for .44 now and am going to be adding 10/.40 and .380, And I
push them hard.

I can heat treat them if needed.

I just ordered 12lbs of this:
http://www.rotometals.com/product-p/...ny_70_lead.htm

and 4lbs of this:
http://www.rotometals.com/product-p/..._babbittsp.htm

I also have 2lbs of linotype.

I'm not familar with the composition of wheel weights in the USA, but here in Europe it is generally accepted that wheel weight contain on average approx 3% Antimony and negligible Tin. If we assume your wheel weights had a similar level of Antimony, then your final mix would be closer to 6% Sb; 3% Sn and 91% Pb with a BHN of about 16 which should be ample for the loads you are contemplating.

Best regards,

Adrian - Germany.