Glock 10 mil.
I lent one to by buddy before we went overseas - he took some pistols out to the sand pit and shot at an old pickup tailgate. The 9s would punch the wall and rattle around inside, but the 10 mils went through the whole unit like butter.
He took the pistol to his CO and said “Why aren’t we issued these?”
The CO said “Good question!”
While morbid to dwell upon (but appropriate to the subject matter of war fighting)...
...a bullet rattling around the intended target, rather than passing right through it, can be preferable.
That is HE went overseas, not “WE”. Typo.