Mikelus watches with satisfaction as his Bolt rounds rip through the Gaunts, preparing to let loose with another volley when the second wave of Tyranids arrives. "New contacts. Engaging the Warrior-form." His tactical duty complete, he returns to privately chanting the Catechisms to himself as he flicks the Fire Selector on his Bolter again and opens fire on the Devourer-armed Warrior.
Spoiler
Switching to Kraken rounds to punch through the Warrior's tough carapace, then firing another Full-auto burst at it.
(1d100)[9] vs 50+20(Fully Automatic)+10(Hulking target) = 80
Damage 1: (3d10b2)[1][1][2](4)+5 (8)
Damage 2: (3d10b2)[2][1][2](5)+5 (9)
Damage 3: (3d10b2)[3][9][3](15)+5 (17)
Damage 4: (3d10b2)[2][5][6](13)+5 (16)
All shots are at Penetration 8. Kraken Rounds remaining: 52/56