[simonrichter]

I still don't get it in every aspect: Imagine you have a fmj .45 acp and a fmj 5.7 x 28 with the same muzzle energy, how would they differ in terms of flight path (ok, that one I can imagine...), penetration, energy transfer in soft medium etc.?

I reckon fat+slow means more drop and thus less accurate range, but what about energy retention after say 100 yrds?

Same for penetration - while it's logical that a bullet which is sleek and fast will penetrate better... On the other hand, while kinetic energy can easily be transfered, but bullets drawing their energy proportionally more from weight than speed keep that factor while crossing through a medium since the weight will remain the same (for a fmj)....