Blending alloys for hardness

[Alstep]

Lets say I have several batches of lead, the exact quantities of lead, tin, & antimony are unknown. But I do know the BHN of each batch. Suppose I take 5# of batch "A" which has a BHN of 10, and 5# of batch "B" which has a BHN of 20, would I get 10# with a BHN of 15? In other words, is there a direct correlation in mixing known quantities of lead with a known hardness, and getting predictable BHN results?

[BNE]

I want to kow this also.

[Liberty'sSon]

Following for answer too.

[bangerjim]

Don't get "lost in the weeds" on this BHN thing! It's not that important. I mix and shoot 9-10 for EVERYTHING pistol and then PC them. For rifles I stay around 14 and PC. PC'ing minimizes the worry about hardness and totally eliminates leading! NO GREASE LUBE NEEDED ANYMORE! Read the stickies.

Buy a CabineTree hardness tester and you can mix anything you want with relatively repeatable results. I do it all the time!

bangerjim

[Bigslug]

Getting totally predictable results? Probably not. There's molecular "stuff" going on in that pot, and if you don't know what's in the dough, you can't know if you'll have chewy or crunchy cookies until you bake them. For example, it takes a smaller percentage of antimony to get the same hardness as it does with tin.

Can you get close enough for "government work"? Most likely, but it will help if the content of one of your additives is known. I would tend to use alloys derived by such means for the less critical applications of low-to-medium velocity solid pistol plinkers and save the known (or more reliably speculated) stuff for competition, hunting, hollowpoints, long range, high velocity - any area where consistent performance becomes more than just a nerdy pursuit.

You've probably found the Fryxell sticky "From Ingot to Target" on the Cast Boolits sub forum. The alloy calculator sticky at the top of this one will also be hugely helpful to you.

Best advice this relative novice can give - hardness-test your Mystery Metals and categorize them as potentially being one of the alloys on the calculator, being aware that while a randomly acquired 12BHN ingot is PROBABLY reclaimed wheelweights, it is POSSIBLY some buffalo-shooter's super-sexy 10/1. Mix accordingly - in small batches if you have severe doubts.

[lwknight]

In a nut shell: NO
But its pretty good for W.A.Gs.

[btroj]

Nope.

BHn tells about a physical property of our alloy but very little about the chemical makeup of the alloy.

Wheel weights can be heat treated to be harder than pure Linotype but they contain far less tin or antimony.

Physical properties are easily manipulated, chemical makeup isn't without changing the actual alloy.

[zomby woof]

No

But close enough

[armprairie]

I melt a lot of reclaimed shot, hundreds of pounds at a time, and it works great, only harder than I like. Air cooling it's about 16 brinell. An old friend of mine had the harder is always better mindset, so he water drops and gets 21 to 24 bhn. For revolver work I like about 12 bhn for your average pressure range 38 special, 44 special, 45 colt loads. If I add 1 part pure plumbers lead (bhn of 5) to 2 parts melted lead shot by volume, I get my 12 brinell. I'm going to be loading up target wadcutters in a few weeks and plan on melting equal parts by volume, hoping to get a brinell of 8 or 9. The best accuracy I've ever gotten from my Model 14 was swaged hollow base wadcutters, brinell of 6.
I have all the plumbers lead and shot in ingots shaped like ears of corn, so it's easy to mix at the ratio I want. It's not an exact science, but more than good enough for my purposes. The lead shot is a special situation because quite a bit of its hardness is derived from arsenic rather than antimony. Results might be a little different with just antimonial lead.

[cwheel]

Most of the lead I have for casting came from unknown origins before I was born. My Grandfather collected scrap lead and melted the scrap into large round bricks to store, and for use later. These bricks of lead ended up being passed from generation to generation along with more bricks of lead being made from scrap lead collected along the way. I myself added scrap babbit along the way as well. No way of knowing what was in the lead, but it works just fine. Come smelting day, I melt the lead bricks in a 50lb. pot on a plumbers pot propane furnace. I was taught by my grandfather before I was 10 ( 55 years ago ) that it wasn't as important " what lead " you were using as it is the density or weight. As we smelted, we would cast into boolit molds that were of a listed weight with Lyman #2 alloy. When our mix in the smelt pot got within 1gr. of the listed weight for the mold, we would cast the smelt pot contents into smaller ingots for boolit casting later. The weight of the boolit casted this way was always very close to the last batch and delivered a very consistent boolit. Another part of the testing during smelting was to take the cast boolit, that was within 1gr. of the listed weight, to a anvil after the mix was right, and stand the boolit on end, hit it with a 2 lb. hammer. Boolit needed to crush to half it's OAL or so, and not crack or split. Had several batches fracture, and we changed the mix so the weight was right with no fractures by adding other lead and changing the mix. I'm not going to tell you that hardness doesn't matter, sure it does. But with lead of unknown types, this old blacksmith method seams to work out perfectly. I've never had problems with to soft of lead, or to hard of a boolit this way. I've had friends that cast and mix much differently and end up with a 125gr to a 175gr. boolit out of a mold listed at 150 gr. Seams like my load workups almost always happen faster with less effort than those who can't hit the listed weight in the loading manuals due to the lead mix. I think when you get the weight right ( density ) this also takes care of the hardness issues for general use. Sure there are folks out there who want a harder boolit to drive it faster, or those who want softer for more upset in the bore when firing BP for example. But for general use with unknown lead lots, this method has worked for my family for more years than I've been alive.
Chris

[armprairie]

That test of standing on end and hitting it with a hammer and it crushing without fracturing sounds perfect to me. It's how you want a bullet to perform most of the time, except my old friend who liked to see .30 caliber hollow points disintegrate in ground hogs. I'm going to start including that test in my methods.

[cwheel]

Stories from my grandfather while doing smelting was of his father ( my great grandfather ) and his family hunting for whatever meat the family was going to get to eat where they lived Canada. The meat for that nights dinner would come from how well he did in the field that day. Long story short, you missed the shot, the family didn't have it to eat that night. No hunting seasons, or tags, just food to eat. Great grandfather is the one who taught my grandfather to cast and smelt. Point stressed was that it wasn't OK to have your rounds impacting all over the place, powder and primers were expensive. ( to them at least ) Best hunt used only one round. Boolit casting and reloading was an important part of life turn of the century Canada.
Chris

[armprairie]

I'm using the hammer test to check mushrooming. I hit a 21 hardness flat point 30-30 175 gr. bullet while sitting on a hard ingot. I'll never do that again without using earmuffs. My ears didn't stop ringing for fifteen minutes and obviously no mushroom either. I used a 3 pound drilling hammer. No fracturing either. I then hit the 16 brinell ones. Ringing in ears not so bad, a little mushrooming, but not much. Then I hit the 12 brinell and started to get some mushrooming, no fracturing, and I can cut it a little with my thumbnail. I'm thinking this is about as hard as I'm going to want to be, maybe not that hard for a lot of revolver work. I also checked Keith style 44's and 45's similarly. I'm mainly looking for good accuracy, not straining my gun or me too much. But I want something that will perform if required.
Chris, that story about your grandfather and great grandfather is just great. How did you ever end up in NV?