STAR WARS: Squadrons

You can get this in AI Fleet Battle. Simply fly around until you are at 5% or lower, kill one of the enemy pilots and you will get it.

Solo vs AI Fleet Battle
Yavin
New Republic
Easy
Y-Wing
Krupx MG7-A Proton Torpedo
Krupx Experimental Piercing Torpedo

On initial launch collide into your capital ship (MC75) until you have 5% or less hull integrity left. That is the tricky bit as you might destroy yourself. If you do this as soon as the game starts I think you may have enough time for a few tries. Easiest if you don't rush this.

Once at 5% or less 5 hull integrity left, stay towards the front of your capital ship. And wait. Do not be tempted to move. Keep selecting the nearest enemy fighter and once within range lock on and fire your missiles to destroy it.

This is easiest against a TIE Fighter as it has no shields. And this works because standard maximum firing range is 1000m whilst your torpedoes lock from 1500m.