Stacking turrets does help with the power of the weapons. if you have 1 cannon it will do 25 damage, but when you put on 2 it does 35 and with 3 it does 43 and with 4 it does 50 and with 5 it does 56 and with 6 it does 61, so you can see a good amount of damage increase with each stacked blaster. now the range I\'m not sure if that changes because every time i tried it would just go out of my sight. anyway stacking AMC will increase damage, this also works for missiles, not only increasing there damage but also there explosion size. well i hope this helps you