Barnes bullet question

[Lone Star]

Can anyone explain why the terminal effects would actually decrease when going from say 2600fps to 2800fps, but increase when going from 2600fps to 3000+fps?

Few real-world graphs of anything are straight lines, but it still seems odd to me that four of six designs show a decrease in depth ar ca. 2900 fps. I can only guess as to why - perhaps the books for that test were not as wet as those used in other tests?

Most certainly for a single design, as the mushroom expands it offers more resistance to penetration, so penetration would be reduced as the velocity increases and the mushroom gets bigger. However, if at one velocity the mushroom blows off - which can happen with Partitions and with X-Bullets and probably with others - the bullet has a smaller effective diameter and would penetrate deeper. But as the bullet loses weight it has less momentum and would penetrate less. The chart helps to put these ideas into perspective. Remember that these were impact velocities (I assume), not muzzle velocities.