Originally Posted by tanksoldier

Most failures of issue weapons I've seen were related to improper maintenance. Everybody wants a better weapon, but what will greater effectiveness cost in weight and training time? How much heavier would a rifle in 7.62 be? How much more would a basic ammo load weigh? Everybody can't have a .50 BMG rifle.

90% of military personnel, even today, never fire a weapon in combat. However, 100% have to be equipped with and carry the weapon, train on it and the people who support them have to be trained as well. Tool sets and spare parts have to be purchased, ammo stocks have to be acquired.

Replacing the M9 might be worthwhile, and the Army IIRC doesn't use the M249 in combat units as a support weapon anymore... maybe some Guard and Reserve guys still have them, but it's mostly been relegated to support troops. However, replacing the main combat rifle would be an expensive and time-consuming process that just isn't justified right now.