Mike is right, it won't work, I tried it right off the bat and it didn't help. Because of the gun's rotation and recoil, if you use laser pointers in the muzzles, the right barrel laser would have to be pointing low left and the left barrel would need to be low right in order for them to shoot together. How much depends on the caliber, the amount of recoil, barrel time, weight of projectile, etc.
Bob