Another little tidbit here, related to some of the posts, but not the original.
Pure lead has a Brinell Hardness of about 5. Lead will begin to deform at a pressure of around 1400 PSI Per BH #. Thus the pure lead with BH # of 5 would deform at about 7K psi. Another thing of note is in measuring the hardness the load is applied to the ball ( for BH) & held for a prescribed interval. Full deformation is not absolutely Immediate. This is why LUP differs from true PSI, the time interval. If loading to the same ballistics with Red Dot & Unique as mentioned Red Dot would produce the higher pressure, but Unique would have a longer time interval. Assuming that both were producing a pressure above the yield point of the alloy being used the pressure vs time would to some extent at least be off-setting elements.
Unfortunately most of us do not have the ways & means of truly doing the Exhaustive Testing which would be required for Absolutely Conclusive data so we just struggle along as best we can. We thus apply what seems reasonable to our conditions.
