The Metal Jacket is bigger than it appears to be on images or in-game, while the main body is relatively small (which includes the head and two little arms). Its big two-paired gossamer wings and the thick tail as well are both twice as big as the main body.
It cries a shriek once an enemy is sighted and will hover in front of them launching Dark Eco blasts at them. Sometimes they will attack with one or two others.
The Metal Jacket has only one attack, though it is an annoying one. It will launch blasts of Dark Eco at you.
It is easy to avoid their Dark Eco bombings, simply keep moving and never stand still.
The Scatter Gun is out of question due to short range. The only gun that works properly here is the Blaster, or the Beam Reflexor. The latter is preferred because the Metal Jacket will be blown aside by one hit, forcing you to aim again with the Blaster. While the Beam Reflexor simply does all the work itself.