However, if you take a step back from it's severely obvious weaknesses, it can be of some use if used properly and in the right context.
The number one use of this gun is while running away from someone who has a much better weapon. On tournment maps, when you spawn near the opponent who just fragged you, it serves as an annoyance while you run away and weapon yourself. Also, when your opponent is far away and you are either too timid or just plain don't have the railgun, the machine gun can serve a purpose if you get lucky and land a hail of bullets, thereby causing your opponent to perhaps run for cover which would in theory result in perhaps a red armor (momentum changing situation) or some other position your opponent was once trying to achieve, but fell short of due to the amount of health he had remaining on his person. The reason i say 'lucky' when i say land a hail of machine gun bullets, is because the machine gun seems accurate at close range but gets seemingly all over the place when used in long distance situations. Obviously the rail is much more accurate at long ranges and much more powerful - great for someone with great aim but it's a one shot deal - hit or miss. The machine gun is an alternative weapon even for someone who has the whole arsenal at their disposal simply because of it's distracting nature. If you're concentrating on railing someone from a distance, nothing is more annoying than getting blood in your view and also when zoomed in, causes your screen to bounce. So you can see that three landed bullets from a machine gun, although only doing 21 points of damage will give you a chance to escape a railshot because you blew their concentration.
Using the machine gun as a primary weapon is normally unheard of, so obviously if you're a novice stay away from it. However in certain maps (tier 5 maps such as q3dm17, 18 and 19) the machine gun can serve as a primary weapon. In order to do this, you must try and reserve space between you and your opponent, and of course have more armor than him/her. Failing to use this guideline with the machine gun as primary weapon will result in damage points done to your opponent, but at the cost of a frag - which in tournament games can be a deciding factor between a win, or a loss.
