Quenching bullits and measuring BHN

[Boyscout]

I have been quenching my cast bullits, waiting three days and measuring the BHN with a Lee Hardness Tool which requires filing a flat on the bullet to test. Is the BHN I am getting accurate? Or, are the bullets case hardened and harder than my test?

[Pat I.]

They're not case hardened so your getting the right results

[462]

This brings up an interesting point, and one that I've spoken to a Lee tech about.

Lead works softens. So, does filing a flat on the boolit soften it, resulting in a false reading? According to the tech's seemingly evasive and dubious answer, it doesn't. I asked about indenting the boolits' noses or bases, and he said "a flat needs to be filed." "Why." "Because that's how we do it." "Okay, thanks for you time, good-bye." I think it's easier for dentists to pull teeth than it was for me to get an informative answer.

I know that experimenting with filing and not filing, and indenting bases and noses will get me the answers. However, prior to getting a Lee test kit, I found three alloys that work for my particular requirements, thus it's not important to know their hardness.

Maybe, if life gets boring, I'll delve into it further.

[Boyscout]

I'm starting out with WW as my base, adding 2% Tin, and hardening with Rotometal 70/30 Lead/Antimony. I worked out a formula (based on a Rotometal hardening formula) on Excel to calculate what amount I needed. I plugged in Desired BHN, Starting BHN and number of total ounces. I shot for a BHN of 19 and got 20.1 BHN actual. I probably should cast a few WW bullets and try again to see how accurate the formula is when I know the actual amount. The Lee tool holds the bullet in a v-shaped trough and the flat provides a clear reading. Also, the Lee reloading manual said bases can be relatively soft from the draw down and may not read accurately.

[geargnasher]

Lead alloy does work-soften. However, not enough to matter to your hardness test. Imagine what the rifling does to it! What matters is how they shoot, and can you duplicate good results from batch to batch.

Most of my boolits have flat noses, so I simply check them on the nose, it's close enough and I don't have to file a flat. Checking them on the bases is not very accurate for a number of reasons.

If you're water-quenching, check a few boolits right after your casting session is over, then again in 24 hours, 48, 72, a week, two weeks, and a month. You'll know then exactly what's going on with your alloy, mould temperature, casting timing, quench water temperature, and the rate at which your particular alloy age-hardens.

Keep in mind that some WQWW can be finished hardening in two days, while other WW alloy might take weeks. A LOT depends on the content of grain-refining trace metals in the alloy like arsenic. WW can contain more calcium than antimony, and those harden differently as well.

Being able to check what's going on with scrap metal alloy is why we buy hardness testers to begin with, right? Use the tool to learn about your particular alloy for yourself, because these days the composition of WW is always a big question mark and there are no standards to go by anymore as to what a given scrap alloy will do when heat treated.

Gear

[NuJudge]

There is a gradient to the rate of cooling of the metal. Hardening is a response to the cooling rate. So long as the flat you file is small and your penetration into the bullet is small it may not make much difference in hardness.

What i remember of my experiments in the lab with other metals was that hardness close to the surface was close to that at the surface. It would drop off more quickly the further in you got.

[1_Ogre]

I have been quenching my cast bullits, waiting three days and measuring the BHN with a Lee Hardness Tool which requires filing a flat on the bullet to test. Is the BHN I am getting accurate? Or, are the bullets case hardened and harder than my test?

I tried it several time, and they do harden, but don't use well water. It will make the boolits seem to have a frost on them. I use bottled water

[Boyscout]

I will repost after I run another batch of alloy and let you know how my "program" works. I have 2x5 gallon buckets of WW's to work through. I will probably try to hit 15 BHN for Alloy 2. I'm trying to find good alloys for my Mosin Nagant, .45 ACP., and .357 Magnum (gas checked). Working backwards my Last WW batch may have been 12.1 BHN. I don't want to waste a lot of expensive 70/30 if I don't need it.

[KYCaster]

Being able to check what's going on with scrap metal alloy is why we buy hardness testers to begin with, right? Use the tool to learn about your particular alloy for yourself, because these days the composition of WW is always a big question mark and there are no standards to go by anymore as to what a given scrap alloy will do when heat treated.

Gear



Another nugget of wisdom from Gear! :drinks:

Pay attention class......pop quiz tomorrow.

Jerry

[RBak]

Another nugget of wisdom from Gear! :drinks:

Pay attention class......pop quiz tomorrow.

Jerry

You're right, when gear speaks you should be taking notes...that is if you're like me and can't remember what you had for breakfast yesterday.

Lots of good information in the man's writings, a lot of new stuff and plenty rehashing of the old, at least to me, and that also goes for several others on this forum, of course.
I suspect that is what makes this such a nice place to hang-out in your spare time between castin' and shootin'.... A fellow never gets enough good learning.

Russ

[Bret4207]

I will repost after I run another batch of alloy and let you know how my "program" works. I have 2x5 gallon buckets of WW's to work through. I will probably try to hit 15 BHN for Alloy 2. I'm trying to find good alloys for my Mosin Nagant, .45 ACP., and .357 Magnum (gas checked). Working backwards my Last WW batch may have been 12.1 BHN. I don't want to waste a lot of expensive 70/30 if I don't need it.

One Scout to another, why are you trying to get such hard alloy? What's the actual reason, the particular thing you've seen with your guns and loads indicating you need rock heard alloy? The 3 guns you mention all work just dandy with straight WW IF the boolits FIT! Fit is King- period! Everything else is just a tool used to tweak your fit, static and dynamic.

If you are going for rock hard alloy based on some formula or, worse, the mistaken belief "harder is better" then you're wasting your time and money friend.

[MikeS]

I will repost after I run another batch of alloy and let you know how my "program" works. I have 2x5 gallon buckets of WW's to work through. I will probably try to hit 15 BHN for Alloy 2. I'm trying to find good alloys for my Mosin Nagant, .45 ACP., and .357 Magnum (gas checked). Working backwards my Last WW batch may have been 12.1 BHN. I don't want to waste a lot of expensive 70/30 if I don't need it.

I would also like to point out that even if you get your alloy to a 15BHN that doesn't mean it's going to function the same as Lyman #2 alloy. Lyman #2 is a very specific alloy of 90% lead, 5% tin, and 5% antimony. It's BHN of 15 is with air cooling the alloy, and because it has an equal amount of tin & antimony it's going to act differently than another alloy that's also BHN 15, but gets there with other combinations of alloy components, and heat treatments. If you want to use Lyman #2, then just mix up an alloy with the 90/5/5 composition, and you'll have Lyman #2. If you just want a BHN of 15 as you feel it's what's needed (for whatever reason), there are a number of ways of getting there. I shoot lots of boolits cast from Lyman #2, and I prefer it to shooting some unknown alloy, but then I'm saving so much by casting and reloading my own that I don't mind using what many consider an 'expensive' alloy (anything with more than 2% tin).

[44man]

I use straight WW mostly, everything else is just an experiment. I don't hold too much stock in actual BNH.
I have a stash of stereo ingots and have been adding 1# to 19# of WW's. BHN has not changed enough to mean anything and the reason I do it is because I have no use for straight stereo.
What I found is the mix makes great boolits, they cast easier and fill out easier. Hard to explain but the alloy seems more "fluid" and stays cleaner in the pot.
I water drop and have found even with a softer alloy for hunting, the boolits shoot better without losing the ductile properties at all. It sure never made a boolit brittle for me, does no harm at all, just toughens them.
I can tell you the BHN but in the end, what does it really mean?
I have found too soft will give me more fliers so I just go a tad harder until they go away. How a boolit shoots is the most important. I will not go any harder then what the guns like.
Hard cast has no meaning but how else to state it? Even air cooled WW metal is hard cast.

[Wayne Smith]

This brings up an interesting point, and one that I've spoken to a Lee tech about.

Lead works softens. So, does filing a flat on the boolit soften it, resulting in a false reading? According to the tech's seemingly evasive and dubious answer, it doesn't. I asked about indenting the boolits' noses or bases, and he said "a flat needs to be filed." "Why." "Because that's how we do it." "Okay, thanks for you time, good-bye." I think it's easier for dentists to pull teeth than it was for me to get an informative answer.

I know that experimenting with filing and not filing, and indenting bases and noses will get me the answers. However, prior to getting a Lee test kit, I found three alloys that work for my particular requirements, thus it's not important to know their hardness.

Maybe, if life gets boring, I'll delve into it further.

What he was trying to tell you, albeit very poorly, is that is the standard by which the instrument is calibrated. Change that standard and your calibration is called into question.

[geargnasher]

Mashing a 5/32" ball into a flat surface on the boolit with 60 lbs of pressure IS the standard. Do you file off surface hardness? Maybe, maybe not. If you're testing the hardness of the surface, that's one thing. If you're testing the hardness of the core at X depth below the surface, that's something different. Which do you want to know?

Gear

[popper]

I don't file a flat spot, just mike the width of the dent after hitting with the hammer.