So what is the best armor hardness? 1. Different tests have different results. An 1944 test with bullet sized projectiles shaped like 75mm shells seemed to show that protection increased steadily from a Brinell hardness number about 200 BHN to 320 BHN. Then slowed the increase from 320 BHN to 360 BHN. Later full size tests didn't show as dramatic differences between armor hardness. Still protection increased from 200 to about 290 BHN. There it plateaued to about 330 where protection slowly declined again. Still other tests showed that the best protection topped at 350 BHN. Probably some of the differences arises is the kind of penetration that is measured. This has been discussed on page 33.
Small scale test results shows the equivalent armor protection. This relative amount necessary for protection decreases as BHN increases from 200 to 320 BHN. 320 BHN is assumed to be the baseline standard for this table. Principles of Armor Protection 1944.[PDF]
2. Program to compare and combine different protection to hardness levels.
3. Relative armor quality can be compared using a number of various benchmarks. Two are the sub-caliber study. Two are from full size tests of the 3" M62 APHE and 3" M79 AP. The average of these four tests look promising in determining relative armor value based on BHN factor. The game normalizes the standard value of armor quality BHN to 270. The US armor tests apparently are normalized to 237 BHN. This would mean the stated penetration of US tests are only 0.9464 of the game's standard BHN. Of course penetration criteria may further adjust this value.
You can now download an improved version of this program at this link> download
3" M79 force function data from the above table was converted to limit velocity and that converted to comparative penetration values. That produced data points for the red line function on the opposite side of the page.