Including a lot of 9mm stuff. I seem to recall reading an article not too long ago that said due to the weapon quantities and routine violence, Hospitals in the RSA treat a lot of gunshot wounds. Most patients walk in. Most were shot with 9mm rounds...

From the 'Marine Rules of Combat:'

"1. Bring a gun. Preferably, bring at least two guns. Bring all of your friends who have guns.
. . .
6. If you can choose what to bring to a gunfight, bring a long gun and a friend with a long gun.
. . .
24. Do not attend a gunfight with a handgun, the caliber of which does not start with a "4."