Don't know if anyone has made the Grey Havens crew aware of this yet, so I figured I'd put a report here. The 4* Shadow Autogun, the "Black Chaingun" does about 1/3 less damage on it's charge attack than the piercing 4* version of the autogun, the Strike Needle. The wiki even has the differences documented on it. From stratum 1, a level 10 black chaingun deals 255-345 damage with all 15 bullets hit on an enemy weak to shadow, where as a level 10 strike needle deals 345-435 with all 15 bullets hit on an enemy weak to pierce in stratum 1. The trend continues all the way to stratum 6, where the black chaingun deals 2475-2625 damage with all 15 bullets on an enemy weak shadow, with the strike needle getting 3375-3600 damage with all 15 bullets on a enemy weak to pierce. The 5* versions, the Grim Repeater and Blitz Needle are equal power in terms of raw damage numbers, leading me to believe that this is a bug.