shot hardness testing

I posted on shot hardness in shotgunworld this thread on my methodology to determine approximate antimony content of various brands of shot. My thinking from reading the LASC article on heat treating lead was that if I checked the hardness of my samples after 24 hrs, the ones that were harder at that time would have a higher antimony content. To any metallurgists on the board is that a logical assumption? Any comments please.

Quote:

We had a discussion at our local Clays field a couple weeks ago regarding shot hardness. What brought it up was the claim on a box of Remington Clay and Field shells of "high hardness shot". I'm a bullet caster who occasionally tests his lead for hardness so I thought I'd check some shot to see if there was any difference between brands and also bagged shot. What I did was melt and cast some half dollar sized ingots of the various brands of shot. I then placed them in a wire basket in a convection oven@430 degrees for an hour. After an hour they were all quenched in cold water simultaneously and aged for 24 hours. I realize depending on antimony content aging continues past 24 hours but at the end of 24 hrs. you will see which has the higher antimony content. I then squeezed a 5/16" ball bearing between the shot ingot and a pure lead ingot which gives me a dent in each ingot. By measuring the dents you can then square each dent measurement and divide the smaller into the larger. You take the answer from that division and multiply it times 5( the Brinell hardness of lead) and that gives you the Brinell hardness of your shot ingot. FWIW here is what I got.
1. Federal Gold Medal 7 1/2 = 21.6
2.Federal Top Gun 7 1/2 =20.3
3. Walmart Federal #8 =18.9
4. Rem Clay & Field #8 =23.8
5. Rem Gun Club #8 =18.5
6. Lawrence Mag shot #8 =12.5
7. Eagle Mag shot #8 =13.4
8. Rem Nitro #7.5 =23.1
9. Win HDCP #7.5 = 24.1

I'm wondering if Remington did not load the Clay and Field loads with STS shot??

The big surprise for me was how much softer Lawrence mag shot was in comparison to Federal and Remington promotional loads. Just thought I'd share my findings.

Back in December of 2016 a fellow going by Mg1polo on Trapshooters.com did an analysis of factory shells of many different manufacturers with a Rockwell tester and posted his results on the forum . Waaay different than your results ! I don't know how to post them here but I could email them to you if you would like or look them up yourself .

I saw those results or something similar (somewhere in the range of bhn 12-7). My results would not correlate to actual shot hardness because I have no idea how hot actual shot is when it hits the water (probably way less than 430F). I'm just trying to determine shot hardness by antimony content and relationship between different brands and price points. If I knew the actual temperature that shot was quenched at my results might be closer to actual.