Chutestrate's continung casting education

[chutestrate]

So if I get 50lbs of lead, I get a bhn of 10 just to know what it is. I need to go through the cast, mold, cool, load, and test the loads I want to see how this batch is going to work in my barrels.

If the content of this batch of lead is unknown (content of tin, antimony, arsenic, etc.) it is going to be a case of trial and error of adding material to this batch of lead to strengthen it. Right?

I want to strengthen this batch of lead to 15bhn. I use one of the alloys from rotometal to do this. Through trial and error I find that if I add 1/2 lb of rotometal's super hard alloy I can consistently air cool the castings to 15 bhn using the lee hardness tester.

My recipe at this point is melting 10lbs of "10bhn" lead, adding 1/2lb of rotometal's super hard alloy to the pot to consistently come out with a slug @ 15bhn.

Now the testing of loads starts again to make sure the slug is doing what i want it to do, right?

Now I get another batch of 50lbs of lead with unknown chemical content that also tests out at 10bhn. Would it be reasonable to to use the recipe from the first batch as a starting point if I want to start strengthening the alloy to around 15bhn?

I'm sorry for continuing to use bhn as a measurement standard in all these discussions, but it allows me to compare the data while knowing I have to take into account all of the other factors.

[geargnasher]

Strictly speaking about the lead recipes, yes, you could assume that. Your actual results will vary based upon what brought the sample up to 10 bhn in the first place. You can bring pure lead up to 10 with tin alone, or with antimony alone, or with a small amount of antimony and heat treat, or a combination of the two. Depending on the composition of the 10 bhn alloy, the addition of you proposed amount of "sweetening alloy" will have a different effect.

For your shooting needs, I'd start with a known alloy and go from there. Once you get things going well with your guns, you can try your "mystery metal" and see how it does. You might be surprised how little all this metallurgy matters with basic cast shooting, as long as you're in the ballpark. Most of the tweaking I do to alloys involves making it cast better and being "just" hard enough for my needs.

Now this is far from the whole story, but a good basic start. You also need to know about age hardening of alloys, as well as the difference between testing an ingot and a boolit for hardness. When you get into high-pressure, high-velocity stuff all this begins to matter a lot, as does composition, particularly the balance between Sn and Sb, and the amount of As if you're heat treating or water-quenching.

Gear

[Wayne Smith]

I think part of the problem here is that your continuing reference to BHN ignores the fact that it is only one part of a complex equasion that includes toughness - a value for which we have no realiable measure. You can have hardness without toughness and lead, you seldom have toughness without hardness and lead except in high pressure cartridges. In high pressure cartridges you need both.

Now you are asking about making alloy without referencing application. In short, what will work for your .45 may not work in your 9mm and 10mm. Or, for that matter, in a rifle.

You say you "want to strengthen this batch of lead" but measurement of BHN is not a measure of strength, it's a measure of hardness. Get this difference in your head firmly and the answers you get will make much more sense. A comprehensive reading of the stickies will be a considerable education, or the alloy section of the Lyman Cast book. There are some good articles on CastPics and on LASCS (?) as well.

Again, you will be told to try it and see what happens. That's because we have no good reliable measurement of toughness or "strength". We have a measurement of hardness, which may or may not answer the question you want answered.

[chutestrate]

I'm sorry fellas, but I just can't get away from the hardness idea. I know it's variable, but where isn't it a part of the equation? Even in the previous post I saw the advice "don't worry about hardness", but it came back to the hardness for high pressure loads. With all due respect to everyone's experience and knowledge it's hard to hear that, and then read that it is a measurement consideration. Kind of a do as I say not as I do thing.

I see now I can't escape the try it and see what happens routine as much as I wanted too in the beginning.

[SharpsShooter]

I sorta see where you are coming from on being able to repeat alloy composition and hardness from batch to batch with a degree of certainty. Foundry certified alloy would let that happen I believe, but that's not economical. So you throw in what you have (example) and create a big batch to last you several thousand bullets. By doing that you have eliminated one of three variables. The second variable to eliminate is diameter selection. Slug the bore and at a minimum strive for a bullet diameter that is .002" - .003" larger than bore. That's two. Three is a little tougher. Select a powder that will produce the lowest pressure and still make velocity you desire. That variable is a trial and error proposition somewhat, but a quick perusal of several manuals will give you good starting points. I too agree with the start slow and work up to the point that gives you the desired degree of accuracy that you require. A clean copper free bore and good bullet lube are of course needed. Don't over think it. The old KISS principle works 99% of the time.

SS

[chutestrate]

That makes a lot of sense, and is probably the best method for my purposes. Thanks!!!

[btroj]

Sharpshooter is right. Don't pverthink it. Yes, hardness is a factor. But I don't think you will see a difference in anything between 16 and 18 bhn. To me there are soft, medium, and hard. That is all. I do not own a hardness tester. I don't have a casting thermometer. I keep it as simple as possible.
I fire up the pot and go from there. No Premixed alloy. Ingots of pure lead, range scrap and some lino. If I want softer, I add lead to the range scrap in the casting pot. If I want harder I add some lino or maybe a bit of magnum shot for the arsenic to aid in water dr hardening. I use a by gosh and by golly method yet it seems to work. Guns seem happy with it from full power 30-30 to various revolvers from big to small. I did learn this year that hard hollow points are bad for deer hunting, too brittle to hold together.

This allot bhn thing is A factor. Capital A because it is one of many. Don't get to wrapped up in it. Try various levels of hardness and see what works for you. In time you will develop a sense of what a certain application warrents and use a suitable alloy. This is part of the learning process.

Could you just buy certified allot from a foundry? Yes, and it would let you chose the hardness you want. Gets expensive though. You will find that most of don't do this because of cost, we casters tend to be a frugal, recycling minded bunch. It is the use of non standard materials that makes the ability to figure out what will work so important. This is unfortunately more art than science.

A good example of a problem with focusing on just bhn is this. I want to hunt big bears. I plan to use a 45-70. I can use wheelwrights and water drop them and get say around a bhn of 25 to 28. This allows me to drive the bullet as fast as my should can stand. I could also use straight lion and air cool it. Same bhn. Also can be driven fast.
So I hit a bear on the shoulder blade. Water dropped wheel weights are , not sure of the technical terms, malleable enough to deform some while holding together. This is a tough bullet. The lion is hard, but much more brittle.on same shoulder hit it could fracture. Poor penetration results. Two bullets with same bhn but much different results on game.

I hope you can see why bhn is a measure of hardness but there is more to the bullet than just hardness.

I know this can be overwhelming for a new guy. Just don't get too wrapped up in bhn. It is number. That is all. Many other factors can have as much affect.

Keep at it. We all started in the same place. Many of us were lucky enough to have an experienced caster give us a hand at the beginning. You will have failures, we all do. I must shot a load today that leaded. Bothers me as to why. Now I have to go find out what is wrong with that load and fix it. This will be a challenge most likely. It is overcoming what does not work where you become a true cast bullet shooter. Doing what works is easy, discovering it on your own is the hard part. Too bad there is not a universal answer but as you can see here, that is not even close to reality.

We all wish you luck. Sadly, luck and a bit of hard learned advice is all the more we can give you. Just don't ever quit learning.

Brad

[casterofboolits]

Listen to the advice you have been given, otherwise you are just beating your head against a BHN wall. All you end up with are knots.

I used to check the hardness of my boolits with a Saeco Tester, but only beause my customers wanted to know.

First step is to slug your barrel. Size your boolits .001 to .002 over bore and shoot them. Document your results so we know what you did and how you did it.

Then, if you have leading, there are other avenues to be pursued to help solve the problem. Powder, powder charge, cases, crimp, rough bore, copper fouling, etc.

Boolit hardness is not the end all that you seem to think it is. It is only one aspet of casting boolits. There is better than five thousand years of experience on this site that you can take advantage of, if you are willing to listen.

[Hickory]

I would not give hardness to much credence as far as being that important.
It is only a scale whereby you can gauge its role in the application of use.
90-95% of your handgun boolits will work just fine with a BHN of 9-12.
The only reason that I can see for lead to be any harder than that is if you are after dangerous game. Such as Grizzly bear or Cape buffalo with a handgun or rifle.
Even with softer alloys 9-12 bhn you can alter the alloy within the same number, let say 12bhn to do several things. If you use X amount of antimony with a small amount of tin to achieve bhn 12 your boolit may not expand as readily as a boolit that is also bhn 12 but has little or no antimony and a lot of tin.
The tin will make the boolit more ductile and allow more of the energy to be spent inside of game.

If you intend to shoot only paper I would use the cheapest lead you have or can get a hold of.
Important thing should to have fun and do your testing with notes, so that when you get older ( I’m guessing your under 60.) you won’t forget what you’ve learned.
:drinks:

[Wayne Smith]

I'm sorry fellas, but I just can't get away from the hardness idea. I know it's variable, but where isn't it a part of the equation? Even in the previous post I saw the advice "don't worry about hardness", but it came back to the hardness for high pressure loads. With all due respect to everyone's experience and knowledge it's hard to hear that, and then read that it is a measurement consideration. Kind of a do as I say not as I do thing.

I see now I can't escape the try it and see what happens routine as much as I wanted too in the beginning.

Sharpshooter made a good point. Once you have found the alloy you want it is important to know, as close as possible, it's composition to re-create it next time around. In part that's why we have standardized on the non-standard wheel weight. In spite of them not all being the same, they are generally close enough.

However, to take any alloy that's not previously tested and predict how it will act in your firearms is not possible. Yes, there are those here that will tell you precisely what a Lyman #2 will do at a paticular pressure/speed/twist rate. Especially those who cast for small caliber rifle. But to take a guestimate at the composition and then try to predict - that's why we say try it and see what it does in your gun. Then you have data points and you can tell us what that particular mix does at a pressure/speed/twist rate.

[chutestrate]

You said it much better than I could have Hickory. I was trying to use the hardness as a gauge for how I was going to use the cartridge. I see now that knowing is such a small piece of the equation that it only becomes somewhat relevant after the other steps are taken. Again, I'm going to back away from my 10mm, probably even recast my slugs for now into .45's, and start there

[HighHook]

This valuable Information you guys are taking the time to write is Amazing. :cool:

:idea:Reading all this info makes me wonder if i should confuse myself and stress over what i am doing is right.

I wish 30+ years ago we had the internet and information like this. We were melting lead and making bullet tips with WW and finding Linotype at swap meets and yard sales and guessing at hardness.

Still today i dont worry to much about hardness and bhn because i just shoot steel plates and paper. I dont push the envelope in velocity. I thrive for bullet fit, good lube, no leading, gun go bang and hit the center of target.

Again! Thanks every one for the Valuable information above. We all have a lot to learn. :drinks:

High Hook

[btroj]

Now you are getting it.
It is a small, but sometimes important, piece of the puzzle.
The key to happiness with cast bullets is getting the whole right rather than focusing on one part of the whole. The hardness needs to balance with intended use, velocity, lube, cartridge, bullet fit, and many other things. Harder can be better in some cases but harder will not overcome the problems caused by ignoring other factors.
Think forest, not trees.

[MtGun44]

For pistols, I find hardness nearly irrelevant even for full power .357 mag and .44 mag
loads with a good design (Keith, LBT, similar), proper fit and a good lube.

I have fired 8BHN and 20+BHN versions of a number of different loads (certainly not
all) with no noticable difference in accy or leading (good, none) between the two. Oh,
yeah - these are all plain based designs too.

IMO, AC WWts will do anything that I have tried with pistols.

Bill

[mike in co]

take a deep breath.......close your eyes.....hummmmmmm gently to yourself and repeat these words................
"BOOLIT DIA IS OF MAJOR IMPORTANCE.....
.....bhn number is of small importance....."

over and over...

OVER AND OVER!

while your pot heats up

is there no where to buy scrap lead in your area ?

mike in co

[chutestrate]

lol, good mantra. there are places to buy scrap. i'm working with a batch i bought from a salvage yard. I have no idea where they get their scrap. All I can do is melt it and clean it. The garages in the area either don't have wheel weights or don't use them. It's a shame

[MtGun44]

Mike is right. Fit is most important. Second most important is boolit design, followed
by lube. After that, I'd put hardness way down for pistols.

What gun and cartridge? Something like .45 ACP or .38 Spl are good for the new caster.

Bill

[mike in co]

Mike is right. Fit is most important. Second most important is boolit design, followed
by lube. After that, I'd put hardness way down for pistols.

What gun and cartridge? Something like .45 ACP or .38 Spl are good for the new caster.

Bill

he was starting with a 10mm...i think he could actually start there..i stared with a 44 mag( and you guys)....but...as has been seen he got wrapped around bhn numbers.....

i think he has said 45 acp will now be up instead of the 10mm

mike in co

[btroj]

45 ACP isn't exactly easy either, too bad he isn't a revolver kind of guy.

With some work, and a lot of testing, he will get it. The drive for knowledge is big. Just keeping on the path is the key. Like I said, think forest, not trees.

[geargnasher]

I'm going to say this again, hopefully it won't be taken the way it was the last time someone said it (not me)!:

Get a copy of the Lyman Cast Bullet Handbook, either #3 or #4, and read with comprehension the sections on casting and alloys. Once you understand the chemistry and physics of what's going on with alloys, the advice given here will make a lot more sense.

Part of the issue with communication here, Chutestrate, is that you lack the basic fund of casting knowledge that the rest of us posting here have, yet have been fixated upon one small but complex aspect of boolit alloy, without even knowing in full context the significance of that aspect. Brinell hardness numbers mean either a lot, or exactly squat depending upon what you're doing with the alloy and how much you know about what to do with it.

For example: I want to cast hollow points for my .45 ACP. I have two choices that are both BHN 13. One is 4% Sb, 2%Sn, .25% As, the remainder Pb. The other is range scrap assayed at 2% Sb and not much else but lead. I take the range scrap, add 1.5% tin to it, cast my boolits and drop them straight from the mould into ice water. After a week, they are 13 BHN, same as the other alloy, yet are as malleable and tough as the 7.5 BHN air-cooled version of the same alloy, and will expand reliably without being brittle, yet are hard/tough enough to be pushed to 900 fps in my gun without leading or skidding the rifling or being too beat-up by the magazine under recoil.

The illustration Btroj gave above with the two boolits of identical BHN that are really quite different is a very good one that points out why we say BHN is really a tiny part of what you need to know. Go back and reread the very first paragraph of my post #2 on this thread, I told you the same thing but in different terms. You need to understand the relationships of the components of boolit alloy. You have to have a basic understanding of hardness, toughness, malleability, the effects of cooling or heat treating, and what each component of the alloy does. You need to know what antimony does, the effect of arsenic, intermetallic Sb/Sn bonds and how that affects toughness and the alloy's tendency to lead or not, primary and secondary phases of crystallization, melt and freeze points and how that's affected by alloy composition, pot temperature, oxidation rates of tin and it's depletion from the melt (molten alloy maintenance), etc. All his is explained in Lyman #3 for sure, and other places as well, and we can help you understand in detail as well, but you have to get into the mindset that you have a lot of information to soak up before you decide what it is that you really need to know, or what questions to ask.

Lasc.us is a great site with some very informative articles about casting, alloys, and such. Glen Fryxell's articles can keep you in fascinating reading for weeks.

Gear

[nanuk]

I remember awhile back asking a NOOB question about hardness vs toughness

I am a hunter first. I want a boolit to perform in that arena. paper punching is only to find a combo that will shoot good enough for hunting

I think it is all black magic

I sure learn a lot from these threads.

[geargnasher]

The way I see it, it's not black magic unless you want to approach it from a mystical perspective :holysheep. Now boolit lube, that's magic stuff! Now my best friend is the IT director for a large advertising agency and he assures me that what goes on inside my computer isn't Black Magic either, and that it's all just science and perfectly logical if you understand how it all works, but I maintain that it's gotta be some kind of electron voodoo.:killingpc

Gear

[nanuk]

Yup.

I think I have spent well over $1k on my reference manuals on guns, bullets, casting etc.

I have all three lyman books. need to get #4
I have a couple P. Matthews books.
I've got a couple NRA books.

and of course I have you guys! one of the best resources!

all great stuff.

my hunting buddy and I are going to get into casting this spring and want to use cast exclusively for hunting this fall if we can get it good enough for hunting.

One other thing, I enjoy reading the forums, and I cut an paste lots of info, and bookmark specific threads that have tidbits of relevent info for me.

Some day, someone will post all this info in a book, and publish it, either electronically or on paper. It would go a long way to helping pay for this site!

I am humbled by the generosity of the posters here!
Wow!