rootninja

Switch to the javelin.

The javelin starts unloaded, so if you don’t switch to it and wait for the loading to complete, this won’t work because it will be an empty launch tube. You don’t have to wait until the full animation completes, just like every other weapon in the game. Once you see the ammo icon in the bottom right show that it’s loaded, you’re done.

Switch to your semtex grenade

The semtex timer won’t start until you let go of it or die. Frag grenades won’t work because you can’t cook them forever, and once you pull one out you can’t switch to another weapon.

Switch back to the javelin

This is probably a technical glitch. Your dead body shouldn’t drop the semtex at all since only the active weapon for the player is normally dropped.

Run kamikaze-style into a group of enemy players

This will be a suicide run, but when you die the semtex will drop and explode the javelin. If you don’t have the javelin pulled out, this won’t work because only your current weapon drops to the ground. If you have the danger-close perk enabled, the resulting explosion will be even larger. I wonder if using last stand with this would have any effect, such as kills from the afterlife, or assisted suicide points for the enemy.

But this is probably just a glitch, and will be patched in the future. So if you want to get banned, please by all means, abuse this!