Max Payne 3
67 Achievements
WMD
Get 3 kills from a single use of the level 3 explosives burst.
How to unlock the WMD achievement in Max Payne 3 - Definitive Guide
When you use this burst at level 3, it will drop a live grenade at the feet of all enemies IN YOUR LINE OF SIGHT. So any enemey you see is most likely to get blown up when you activate this burst but this isn't always the case as they have a few seconds to dodge or escape the blast.
So your best bet here is to find a spot where there's at least 3-4 enemies at once like around an objective or something and use your burst then and just hope you get at least 3 kills within the burst you use.
Equip the 'Explosive Burst' to any of your loadouts. Hop into a Gang Wars game and proceed to get a couple kills until your Burst meter reaches Level 3. Melee kills will fill up the meter faster than regular kills.
This Burst essentially drops a live grenade at the feet of all visible enemies on the map. Your best chance to get this legitimately would be to wait until there is a round of 'Turf Grab' , as the chances of the enemy team being bunched up are high. Once you see at least 3 players on the enemy team, activate your Burst and hopefully the enemies die from the explosion.
If boosting, simply follow the same steps to get your Burst meter to Level 3, then have your partners stand in a circle right in front of you while you activate the Burst. They will all drop a grenade and once the explosion kills them, the achievement is yours.