Our military adopting the Grendel?

[stanc]

That's a good test to do, I think! Have you done it with 855?

Yes. 15-20 years ago I did it with 5.56 M855 and 7.62 M80.

M855 penetrated the front, but only cratered slightly the back. M80 punched clear through one block, and through the front of another block behind the first.