Reading spent cast bullets

[BJung]

I pulled these spent cast .45 bullets from bullets I was melting. What can you tell me about these bullets besides them being "flat".

The bullets were shot at a 10 yard indoor range at a steel plate backing postioned at 60 degrees. The rules are that the bullets must be shot below 800fps but 700fps could be possible. I used art pencils to guess what the BHN was. The BHN varied from 9-11. One bullet scratched at 9BHN, two scratched at 10bhn, and of course, these and the rest scratched at 11bhn. What would you guess the bhn would be and the MV. I will test this lead along with .22lr lead and air rifle lead for HP testing and I think these .45 bullets were from one of these lots. I don't know who the shooter is but it's a small club. My question is, would a soft bullet and lower MV of arond 730bhn be able to flatten a lead bullet like this? I'd guess it was a SWC.303178303179

[Froogal]

The bullets that I cast result in a bhn of about 10, and usually just flatten out into a disc shape after hitting the steel target. I will guess that the fragments in your picture were somewhat harder than 10 bhn. In my experience HARD bullets have a tendency to just shatter. Sometimes the pieces are too small to even pick up.

[mdi]

I think the 60 degree plate adds to the deformation and the tearing/fracturing. To me they don't look too much like hard lead shattering, no jagged pieces, mostly "torn", "smushed" pieces. I'd say the alloy is pretty soft but can't guess at a BHN (10-11 maybe)...

[Kosh75287]

"Reading" cast bullets could turn into "a thing", if you go about it systematically. The 60-degree plate angle obscures some things, but if you fire various calibers of bullets of known hardness at known velocities (say, 600 f/s to 900 f/s, at regular demarcations), you could use the recovered projectiles as reference points.
Instead of firing them into a steel plate, firing them into a row of water-filled gallon milk jugs might "shred" the projectiles less, and add a measure of penetration to your analysis. It would be some work, but likely informative.