Grenade Launcher–Somewhat averted, in the sense that the modern infantry soldier in powered armor usually has vector manipulators that can toss a grenade very far. However, there are circumstances where you need a lot of grenades on target in a short period of time, and that’s where modern grenade launchers come into their own.
A grenade launcher is basically a lower velocity grav gun, firing standard grenades very fast and in very large numbers. This is very useful when dealing with Changelings on the ground, since they attack in huge swarms. It’s not quite in the whole More Dakka category, mostly because there are vehicle-mounted grenade launchers for grav IFVs that put out even more grenades, and larger grenades.