Blasters fire bolts of energy that, like all other E-tech weapons, deal additional elemental damage and have different effects from their standard counterparts, at the cost of 2 ammunition per shot. They have lower muzzle velocity than standard weapons of the same type.
As with most weapons, different manufacturers' Blasters have significantly different effects from each other:
Dahl: Spread gun which fires straight ahead and at roughly 30 degrees to either side. Unscoped fire alternates between the three angles consuming 2 ammo per shot. While scoped, burst-fires on all three angles at once. The burst fire shoots 9 projectiles total (1 in each angle, 3 times) but only uses 1 ammuniton per projectile.
Vladof: Blaster bolts ricochet once off most surfaces. As a Vladof weapon, fire rate is extremely high. Always consumes 2 ammo per shot.
Both types of blaster have an accuracy below par and are best suited for medium to short range (specially the Dahl version). Since these guns can consume ammo very fast, it is better to use or have a Gunzerker in the party who can regenerate ammo or simply switch to a different weapon type from time to time. In early stages of the game, the entire assault rifle ammo can be depleted very quickly.
Blasters can be frustrating to use while in fight for your life state due to the wide bullet spread as well as trying to shoot flying enemies due to the reduced muzzle velocity for e-tech weapons in general.
Vladof blasters can be useful for fighting armored spiderants, by aiming below their body and letting the ricochets make critical hits against their underbelly.
Krieg's Pain is Power skill, when boosted above 5, will cause the Blaster to deal less damage on a critical hit than on a normal hit, due to the already low critical damage this weapon does.