I have just attained it in my new character and oh boy it makes farming for XP on alien planets so much more fun. Conceptually I'm not proud of genociding innocent alien creatures for fun and profit but animal brain sees big boom and number go up = big happy.
also if it isn't obvious why I call it the war crimes shotgun, somehow this caseless ammo space double barrel can be made to shoot what's essentially fragmentary explosives? even being ostensibly a gun nerd I don't give a shit about how little this makes sense, the guns in starfield are mostly pretty good. the automatic rifles being so low damage is bullshit however, they become kinda obsolete by the late game since enemies start having 4 health bars and crit perks don't apply to automatic guns.

