Looking at this in a weapon point of view, what would be the more effective one? Say we have a 155mm projectile travelling and hitting a hard target(metallic), lightly and heavily armored, at different times, both with an impact energy of 530 MJ. Also say we have a very short IR laser pulse with a beam diameter of 155mm also hitting lightly and heavy armored targets, with an energy of 530 MJ. What would be the effects of each in a vacuum? Would it change very much to do it in atmosphere (besides the associated drop in velocity with more range for the projectile)? The projectile most definitely seems it would be much more devastating but I just wanted to get some realistic answers on this.