The fuel rod gun is one of those weapons in which they are the most useful only under certain circumstances.
Only use the gun when you have a good amount of distance between yourself and your target. Too little and you will harm yourself in the blast, to much and your target will move out of the blast zone before the rod reaches it. Try to aim for the ground in the middle of a group of enemies, instead of for individual enemies, because it is very easy to miss and have the rod fly
harmlessly by. Aiming for the ground will use the splash of the gun to great effect.
Also, even though the gun has a clip of five rods and it can fire very quickly, you must be conservative. Often one or two rods is all that is necessary to eliminate a threat, especially if you take your time to aim. The fuel rod gun also has a powerful melee, but you should never be close enough to an enemy when
wielding the gun to have to melee.