Testing the hardness of your lead balls

[ApprenticeBuilder]

I went and read up on your lead tester, it seems to be a nifty gadget but I see an issue with getting accurate results consistantly.

TESTING: Run the screw point until it just touches the sample. For a bullet, this should be centered and preferably on a flat (if there isn't one, file a 1/4" flat for a better test). After the point just touches the sample, note the EXACT pointer mark, rotate the screw EXACTLY ONE TURN, and read the indicator. You have just made a test and it probably took less time than reading this. Note: On pure lead, read the dial quickly as the spring is strong and the point will continue in changing the reading. This isn't a problem on harder alloys.

NOTE: IF you use exactly the same procedure each time your results will be consistent. Varying the "first touch" will cause the most errors. Concentrate on that first touch. On hard bullets, they can literally be held in place by that touch, BUT on pure lead just a hint of a touch is correct. On pure lead any touch is penetration and it will give you high readings.

For the larger pieces of lead the drop test or tinking them together with a known soft piece of lead works about as well, once home with the lead pour a few balls then an accurate test can be completed.

The only lead I buy off the net is sheet lead, in sheet form, period.

The plug I made to fit the Saeco tester for round balls.

 

[Idaho Ron]

Yes with pure lead the tip will sink and the dial will continue to drop for a bit. But the fact is that is 5 BHN. no lead is less than 5 BHN. once you add some alloy like I do to get the hardness I want the dial is steady. So if the lead is soft enough to sink it is 5 BHN. I don't see the problem. No other tester is going to be as versatile as this one.

 

[necchi]

Ron,
Do you have a link for that "nation wide" test that was done,, I believe you participated.

For those that don't know, samples of the same lead was sent to several people with different testers across the country,
The resulting compiled info was quite interesting.
It didn't really prove or disprove anything besides how an individual uses the tester is what matters.

Almost like a micrometer or dial caliper,, the reading someone takes only pertains to that individual,, others readings may vary but what matters is the individual can use the data as comparisons to his own work/goal.

 

[Billnpatti]

Love it! If it is as accurate as purported, it is ingenious. I am putting it in my permanent file for future reference. Thanks a million!

 

[Idaho Ron]

I think this is the one.

http://www.lasc.us/Shay-BHN-Tester-Experiment.htm#CabineTree

 

[Alden]

Good man!

 

[ApprenticeBuilder]

Thanks for that link, interesting reading for sure.

Was amazed at the variations within each of the various manufacturers equipment.

 

[Idaho Ron]

Like was noted on the test. For us guys that buy a tester the most important thing is not the actual BHN. The most important thing is that your lead's BHN is the same every time. Although I have tested mine many times and I have always been close to actual. it is like anything they more you do it the better you get. Ron

 

[ApprenticeBuilder]

It is obvious that the key to this is repettition, this would help to eliminate variables.

I am curious though, was this test conducted with random individuals that knew nothing of the others involved ? I am interested in the numbers posted by several of the Saeco testers that showed exactly the same all the way thru the tests, is it coincidence or ?

Either way thanks again for posting that information, very interesting.

 

[Idaho Ron]

None of the testers knew each other. Heck I don't remember what number I was now. I still have the bullets that I tested. Ron

 

[M. De Land]

It was recently discovered that pure lead does not actually have a Brinell hardness number (BHN) of 5. It is more on the order of 4.6 so can throw some calibrations off.
But as has been mentioned the actual number is not important for personal use but rather the comparative number that can be reliably indicated by the tester used.

 

[phoenix511]

Assuming the ML shooter wants pure, soft lead for projectiles, here's another way of confirming the alloy you are using is pure enough:

A tangent to the BH issue: assuming pure lead (99.9%) is desired, one can make a rough estimate of the purity of the material by comparing the volume of a sample with the specific gravity of lead. Any metal other than lead (except gold) that can be alloyed with lead has a lower specific gravity, and it doesn't matter, for this calculation, if it is tin, or antimony, or silver, or anything else. (If you have gold mixed with the lead you are using, you have a another problem to solve.)

You will need to do some converting of Kg/M3 to grains/in3, but the result is 99.9% lead is 2866.7 grains/in3. My 50cal mold makes a ball 0.489" diameter, which is 0.061 in3. Thus a 99.9% lead ball should weigh 176 grs. Mine weigh 174 grs, so an approximation is 174/176 for 98.9% lead.

 

[mooman76]

Rarely are ball moulds perfectly round. They may be close but not perfect and what about air gaps? If they were perfect every single ball would come out exactly the same by weight.

 

[necchi]

Yeah your right, the math is correct,
But using the formula with individual ball isn't really practical, it would need to presume a perfect sphere, absolute purity (sans slag, dirt or air bubbles) and no sprue.
The simple human factor of casting error always lends a variable of +/- a few grains during the cast session, even after culling a tight tolerance of acceptable ball for our use is keeping all ball within +/- .5grn of average.

 

[Idaho Ron]

I would also add that just by adding alloy doesn't necessarily mean a projectile will be lighter. On bullets adding a little alloy can help the mould to fill better thus allowing more lead into the grease grooves of a bullet. I don't pour balls so I can comment to using them that way. Ron

 

[phoenix511]

Yep, my method is only an approximation for those with calipers/micrometer and a powder scale. Yep, the bullet is never a perfect sphere, and there is variability from ball to ball, and it does not measure hardness ... but close enough, in my opinion, for approximating the lead content of the sample. Measure & weigh a sample of 5 or 10, see what variability you get.

I'd suggest if you get results showing perhaps 95% lead or less, the alloy has lots of something else. But you'd already know that as they would be too hard to load easily.

This method only works with round balls. It can be used to determine the approximate lead content of the alloy, so if casting Minie projectiles, all you can say is the alloy is about XX% lead. Anything added to the alloy will make the specific gravity lower (other than gold) ... but maybe make for better casting properties.

 

[Idaho Ron]

I don't see how that would be any more accurate then dropping a ingot on cement. Ron

 

[nkbj]

Listening for the ring on cement has worked for me.
Looked at the two bullets in the vise method and decided that bullet hardness was like how much oil to put in the pan for taters. What worked did.
So I make a batch of bullets and see how they work. More powder, less powder.
But like taters sometimes it doesn't work out.

 

[Ken Cormier]

Wow learned more about lead than I needed lol