Originally Posted by Patchman
Conflicting standards, perhaps.
FMJ are required for armies under the Hague Convention of 1899. That convention moved away from expanding type bullets because they were deemed too cruel.
One of the big reasons that was agreed to is because they are arguably more effective in a war scenario. If you severely injure a soldier, you have the potential to stop multiple soldiers from fighting, vis-a-vis an additional soldier or two helping the wounded get clear of fire and get medical aid. Kill him, and you have only take out one.
The arguments that have held up in court in favor of JHP are:
1. They stop the threat more quickly.
2. They have less tendency to over-penetrate *as you stated
3. They have less tendency for ricochet.
I'd also like to point out that in war, over-penetration is a GOOD thing. goes through some light barriers, has the potential to wound additional targets, etc. In civilian life, we don't really want that. A 45ACP ball might be ok on a fat target, but a 9mm or 357sig in hard ball will go through most targets, no matter how obese. And they would do very little to ensure a quick stop to the threat.