My homemade comparison hardness tester gave out when the differences between pure lead and the heat treated stuff were compared. So I decided to try a Lee Hardness Tester. Got one yesterday and spent the evening playing with it.

There are lots of good and a little bad. First, it is inexpensive. There are those who believe inexpensive and cheap are the same thing. I don't believe that. This is inexpensive ($35 from Midway).

Second, it is easy to use. 5 minutes of reading the instructions and I was off measuring hardness.

Third, it has a pretty high tolerance for goofs. I deliberatly tried some of the things they said NOT to do (like pushing the center plunger so it was 1/64" higher than the top instead of flush). The errors were barely measurable. In addition, you have to get pretty far off of perpendicular to get bad (non repeatable) reading. However, it is necessary to smooth off (file) a flat spot like they say to get a good reading. If it is not, the "dimple" in the lead will not be round.

Fourth, it matches pretty close with the some of the numbers I was getting with my homemade comparison tester.

Inbetween (not good or bad). The Lee tool uses a magnifying glass with inches marked on it. This is often used in industry and is often called a comparator (sp?). It is not really difficult to read, but it does take a little practice.

Now for the bad part. It is not of much use for CAS shooters. The calibration scale that comes with the tool starts at a Bhn of 8.0 and goes up from there. If you have pure lead, you won't really get a reading, other than "less than 8.0".

I plotted a graph this evening with the table values that came with the tool. It is not a straight line, but it is a low order (exponential) curve. I will eventually get my kid to enter them into his math program and have it make a best case match. Until then, I extended the line with my French curves like I have done many times while doing stress analysis. I will try that for a while to see what my softer lead is.

Now for the results: My mixture of 1# of monotype to 2# of pure lead (air dropped on a towel) came out to be about Bhn 15 with my old comparison tester. It came out to be between 16.6 and 17.2 in several tests with the Lee tool. I know the difference now. I was assuming the certified pure lead I was using in my comparison tester had a Bhn of 5.0. It was probably softer, possibly as soft as 4.4 for really pure lead. That would have made the numbers closer. I was not able to get a good reading after heat treating the same bullets with my comparison tester. The Lee tool gave readings between 27.2 and 28.5.

My 40:1 41 Long Colt bullets showed a dimple of between 0.096" and 0.100" diameter, which is far below the chart Lee provides. Although this mixture is supposed to be about 8.5 in most books, it is far softer than that with the Lee tool. I also tested some certified pure lead at 0.116" to 0.122". My ingots of pretty pure roofing lead are a little harder at 0.102" to 0.108". I think the pure stuff is probably about 4.4 and the igots are about 5.0, but don't have anything to back that up yet.

Hi Harry! Very informative post. But I know nothing of this testing and have a few foolish questions. Could one just use the flat base of the bullet and not file a flat spot for testing? ( Would you think the file would change the metal being tested?) And do your tests of most metals compare with what"advertised" figures say? I heat treat right out of the mold but have only simple tests. Will my thunbnail scratch,scrape, or just polish it? I know that properly heat treated bullets "ring" ( well, sort of) when clanged together. Have you ever noticed this? Thanks, Dale

The kit has three parts and is intended to be used in a standard reloading press. One is a V-block that fits where the caseholder goes. The lead piece fits onto the V-groove. That means that it would be hard to test the bottom of a bullet. The round sides of a bullet fit in the V-groove very well. A bullet nose would not.

Working lead will harden it (just like working most other metals). That means that if you size a bullet, the surface would be a little harder than the center. However, I believe that the difference is small. I base this opinion on the fact that I used test steel, stainless steel, aluminum, and exotic metals (inconel, monel, etc) with tools similar to this (except MUCH heavier and MUCH, MUCH more expensive when I worked 20 years in a metal fabrication plant. Work hardening is a surface phenomenom. Besides, if your bullet has random hard and soft spots, it probably would not be very accurate.

The other two parts are (1), the magnifying glass (comparator) that I mentioned earlier, and (2) the part that is screwed into the press where you usually screw in a reloading die. It has a round ball on the bottom and is spring loaded. There is a tube in the center that is open to the top of the tool. You raise the handle of the press (which presses the ball into the lead) until a center rod in the tube comes up flush with the top of the tool. Then you hold it there for 30 seconds. I also checked 10 seconds on either side of that and found that (at least with soft lead) that it made a very small (but readable) difference.

The comparisons I have with my "homemade" tester are pretty good, but I know that the homemade one was not good enough for fractions of a Bhn. I don't know if this one is, but I have found out that the readings are pretty consistent (repeatable). Even if they are not totally accurate, they would be very good for comparisons (actually, that is how the $100 SAECO hardness tester works -- pure comparison).

Harry, Did you intend to say working lead will harden it? Everything I've read (Dennis Marshall's articles)about bullet sizing says the opposite: If you size a CB, you soften that part which is reduced; more sizing means a greater depth of softening. You may want to consult Marshall's article, "Cast Bullet Heat Treatment" in the RCBS Cast Bullet Manual, number 1, particularly p. 32. Enlighten me, ...Maven

Ok Harry, Thanks. I think I understand a lot more about it now. I am a bit confused on one thing , however. Somewhere I got the idea that sizing a heat treated bullet softens the lead displaced by the sizing die. I go to a lot of trouble ( I made a tool to crimp gas checks on without sizing and then I run the bullet thru an oversized die to lube but not size.) because I believed this. Hmmmm.... Thanks Again, Dale

I need a tester, and have been eyeing the Lee. What I would like to know is how it compares to the SAECO, is it as accurate and maybe just harder to use?

Paul: I rechecked my casting books and you are right. Lead softens on working. I did not do any lead testing at work. Just steel, stainless steel, aluminum, etc. They all do work harden. No if, ands, buts, or maybes. Not so with lead (according to the books). Sorry.

I have not used the SAECO so I don't know much about it (other than it uses its own comparison scale). The thing that is most important to me is, are the tests repeatable. It appears from my tests so far that they are.

HarryO: As I recall, tungsten is another material that softens when worked. To make it malleable enough to draw into wire to make light-bulb filaments, the starting material has to be beaten and tweaked throughout the diameter-reduction process. Not much applkication here, unless you've got a stash of tungsten AP cores. floodgate

Harry O,

I picked up a Lee myself not that long ago and I like it. Like you discovered the chart provided by Lee did not cover the working range you might encounter in casting bullets. What I did was punch the Brinell formula into a spread sheet and calculated the results for indents from .001" through .100" since I didn't know what the results would be. If it helps your results for the .41 Long Colt of .096" & .100" return as 5.2 BHN and 4.7 BHN. Based on the numbers I've seen I could have started at .040" or 33 BHN since heat treated WW's high numbers were 29.9 BHN which is .042" by the comparator. I extended the numbers in my spreadsheet and your values of .116" to .122" worked out to 3.3 BHN and 2.9 BHN. Your ingots of pretty pure roofing lead at .102" to .108" equated to 4.5 BHN and 4.0 BHN.

Hope this helps, Later...

Has anyone done hardness testing on random wheelweights? I ask because I'm wondering if hardness could be a way to find some of those reported European zinc weights. I melt about 400 lbs at a time, and hate to mess with segregating that many WWs one at a time.

Grumble
Check on Theantimonyman site I believe he states not to melt w/w over 650deg's to prevent them from getting in the alloy. The last time I melted there was a couple weights floating with the clips and they went to the trash.Since this might be a problem in the future I am going to save them and run some test on them and see if they will cast or not.
Be careful Dye

Thanks, Dye. Good info. The problem, for me anyway, is that it's so hard to control temperatures in a big melt. Throwing in a few handsfull of WW in a 100+ lb melt changes the temp a lot, and when adding weights to a nearly empty pot, it's almost impossible to regulate the propane flame accurately enough to be certain of any particular temperature.

So much for my whining. <GGG>

I have some weights that look suspicious to me. They're shinier than most of the weights, and they have two numbers (ounces and grams?) on them. They also have some sort of letter code, like AW, AL, etc, and are sort of "square" ended, not pointed like most weights. If these are of a different hardness, they would be easy to separate visually and melt in a segregated batch, just in case.

Thanks again for the info!

I'd suggest testing a wheelweight suspected of being zinc in sulfuric acid, about the strength of battery acid. If it's zinc it'll bubble furiously as the zinc turns to zinc sulfate, liberating hydrogen gas. Lead ones won't do much.