Build yourself Once you hit lvl 5, go to the menu and go into pilot loadouts. You can click on any pilot loadout and choose your primary weapon, like the R-101C CARBINE, choose Iron Sights as attachment, then Factory issue as the Mod, Achievement unlocked.
To use the load-out in-game you have to choose your load-out upon entering a match, It took me a while to find this out..... Thats for if anyone was wondering.
Good luck and have fun!