The spread remains consistently tight when firing outside of V.A.T.S. mode; however, when firing within VATS mode, a registered "miss" will make the spread much wider than it is outside of VATS mode (though some beams may still connect with the target, doing slight damage). Because of this and the single critical/shot limitation of VATS, this weapon is far more effective outside of VATS.
The 55 base damage is split between each of the nine beams, but outside of VATS each beam can cause a separate critical hit doing +27 damage per beam. Furthermore, a sneak attack critical automatically score critical hits with all beams The combination of a sneak attack and the better criticals perk will result in 839 total damage.
The Metal Blaster's laser beams won't set off any gas leaks if shot from a distance. However, if the player shoots while standing in a cloud of gas, the explosion will occur just as if it were a "regular" firearm.
Everett explains that it was created by a man from The Pitt using parts he found lying around the The Mill, including a series of prisms that split the beam. Everett came into possession of the rifle by looting the man's corpse in The Mill.