Cutting Rotometals Foundry lead with pure for 40s&w 9mm and 45

[40sand9s]

Good afternoon,

My brother and I have started shooting a lot more often now that he has moved back into town and we are looking to shoot a lot more pistol rounds and xtreme bullets are getting expensive. I have been lurking this forum for several weeks and the white box in the top right has been heavily utilized however I am still left with questions. When looking at other posts it seems like rifle rounds, magnum pistol, and all other get blended together which makes a new caster a bit confused on just how hard bullets need to be. My main goal is to keep cost to a minimum with pretty decent ammo at an affordable cost to shoot 300+/month minimum.

Rotometals has foundry lead for sale for 13.6/ bar which consists of 64.5 lead 23 antimony and 12.5 tin which seems like a pretty good bang for your buck due to the large amount of tin and anitmony and lends itself to being cut with lead. Before I started reading on the site I thought lead was lead so I bought 150lbs of a mix of water pipe, roof flashing, and rolls of lead that are about 3 inches wide and a foot or more long that are all pretty soft for .80/lb which seemed like a good deal but later realized cannot be used as is..

These will also be tumble powder coated with hf red since this seems easiest and most cost effective to get started. I plan on using lee 6 cavity molds for speed and water quenching to get a little extra hardness.

I have used the calculator on this site where the first line is pure foundry and each additional line is an extra lb of lead added. Could someone please point me in the right direction as to which mixture would get us to where we need, the range is a while away so trial and error on my end would take forever. I appreciate all the help and apologize for such a long post. columns are tin/ antimony and end with lead.

Custom Alloy 12.50% 23.00% 0.00% 0.00% 0.00% 64.5% Brinell 33 $0.00
Custom Alloy 6.25% 11.50% 0.00% 0.00% 0.00% 82.3% Brinell 21 $0.00
Custom Alloy 3.13% 11.50% 0.00% 0.00% 0.00% 85.4% Brinell 20 $0.00
Custom Alloy 1.56% 5.75% 0.00% 0.00% 0.00% 92.7% Brinell 14 $0.00
Custom Alloy 0.78% 2.86% 0.00% 0.00% 0.00% 96.4% Brinell 11 $0.00
Custom Alloy 0.39% 1.43% 0.00% 0.00% 0.00% 98.2% Brinell 10 $0.00
Custom Alloy 0.20% 0.72% 0.00% 0.00% 0.00% 99.1% Brinell 9 $0.00

Thanks for such a great site and can't wait to hear what the pro's have to say.

[Chill Wills]

Good afternoon,



I have used the calculator on this site where the first line is pure foundry and each additional line is an extra lb of lead added. Could someone please point me in the right direction as to which mixture would get us to where we need, the range is a while away so trial and error on my end would take forever. I appreciate all the help and apologize for such a long post. columns are tin/ antimony and end with lead.

Custom Alloy 12.50% 23.00% 0.00% 0.00% 0.00% 64.5% Brinell 33 $0.00
Custom Alloy 6.25% 11.50% 0.00% 0.00% 0.00% 82.3% Brinell 21 $0.00
Custom Alloy 3.13% 11.50% 0.00% 0.00% 0.00% 85.4% Brinell 20 $0.00
Custom Alloy 1.56% 5.75% 0.00% 0.00% 0.00% 92.7% Brinell 14 $0.00
Custom Alloy 0.78% 2.86% 0.00% 0.00% 0.00% 96.4% Brinell 11 $0.00
Custom Alloy 0.39% 1.43% 0.00% 0.00% 0.00% 98.2% Brinell 10 $0.00
Custom Alloy 0.20% 0.72% 0.00% 0.00% 0.00% 99.1% Brinell 9 $0.00

Thanks for such a great site and can't wait to hear what the pro's have to say.
Just doing the math in my head....
If line one is one pound, then;
I think in fact each lower line represents double the lead in the last line, not just an additional pound.

Having said that, alloy and hardness for your pistols have not been stated and depending on what you are shooting and what your loading goals are soft or hard alloys may be needed.
In other words, whatcha shooting? :bigsmyl2:
This is not what you wanted to hear but a little more info from you would help.

BTW, you are on the right track. Doing your homework is always a good idea! And this is not all that hard, after you do a little of it you catch on and you will be fine.

[runfiverun]

bhn 11's alloy is probably the closest to what I'm shooting in my 9's.
if I want harder I drop from the mold into some cold water and it's closer to 18 bhn
the bhn could be 9 or 50 and it wouldn't matter if my boolit didn't fit, I'd end up with lead smeared everywhere down the barrel.
but since mine fit's I run my velocity down around 850fps [which just barely functions the guns] up to the same load I used under the jacketed bullets I used to buy in the 80's.

[40sand9s]

Thanks for the reply,

My math was off pretty bad however it looks like the good result for me is each additional lb doesn't dilute it as much as originally thought. That's what happens I guess when you try to get stuff done in too big of a hurry while your 2 year old is asleep.

Custom Alloy 12.50% 23.00% 0.00% 0.00% 0.00% 64.5% Brinell 33 $0.00
Custom Alloy 6.25% 11.50% 0.00% 0.00% 0.00% 82.3% Brinell 21 $0.00
Custom Alloy 4.13% 7.59% 0.00% 0.00% 0.00% 88.3% Brinell 17 $0.00
Custom Alloy 3.13% 5.75% 0.00% 0.00% 0.00% 91.1% Brinell 15 $0.00
Custom Alloy 2.50% 4.60% 0.00% 0.00% 0.00% 92.9% Brinell 14 $0.00
Custom Alloy 2.08% 3.83% 0.00% 0.00% 0.00% 94.1% Brinell 13 $0.00
Custom Alloy 1.79% 3.29% 0.00% 0.00% 0.00% 94.9% Brinell 12 $0.00
Custom Alloy 1.56% 2.88% 0.00% 0.00% 0.00% 95.6% Brinell 12 $0.00
Custom Alloy 1.39% 2.56% 0.00% 0.00% 0.00% 96.1% Brinell 11 $0.00
Custom Alloy 1.25% 2.30% 0.00% 0.00% 0.00% 96.5% Brinell 11 $0.00
Custom Alloy 1.14% 2.09% 0.00% 0.00% 0.00% 96.8% Brinell 11 $0.00

I think this is correct but if not please let me now. I am currently casting 9mm for a glock 19, taurus 709 slim, hi-point carbine, and sterling sporter carbine. The 40 is for a h&k p2000 and 45 is an ati 1911 gov. I am just looking for plinking loads and hitting some steel that will cycle my guns. I prefer softer rounds simply since they would allow me to use more lead for a cheaper bullet, I don't think beer cans know the difference but also want to be able to knock down a steel popper when shooting matches at my club.

I am hoping to be on track and appreciate the support. I kinda have an addictive personality which can attach to anything and it looks like cast is where I am headed. Once I find a good mix I'd like to cast several thousand rounds, coat, and shoot for a while without having to mess around much.

[DerekP Houston]

Custom Alloy 1.25% 2.30% 0.00% 0.00% 0.00% 96.5% Brinell 11 $0.00
Custom Alloy 1.14% 2.09% 0.00% 0.00% 0.00% 96.8% Brinell 11 $0.00


This is about where mine ends up after mixing with range scrap. Most of my stash is from a source of 95/5 antimonial lead, I just sweeten it with a bit of tin from here and use as is. With the high % of antimony in that foundry type you probably won't need much to adjust the pure lead you have.

[C. Latch]

If you bought an alloy that was 23% Sb and 12.5% Sn you could mix one pound of it with 9 pounds of near-pure lead and end up with an alloy that was roughly 2.3% Sb and 1.25% Sn, which is going to be similar to plain old wheelweights and ought to make perfectly usable bullets for semi-auto pistols.

[40sand9s]

Thanks for the help guys,

I ordered 8 bars from rotometals to get my free shipping and will let you guys know how it goes. It will probably be a few weeks until I start casting while I find some time and finish reading the lyman casting book.

[Wayne Smith]

Start with your 45's. Almost pure can be used in that, so very soft is OK as C.Latch said. There is a sticky on loading lead in 9mm's - read that through probably twice. It will be your most challenging round. Fit is king, but hardness compared to pressure is probably Queen or Prince. If you do the 9/1 mix you can water drop it for the 9mm and it will be hard enough. You can use air dropped ww metal for the 40 with no problem, so the 9/1 will work for that and your 45's. That will get you started, give you some experience and confidence that you will need when working up your 9's.