Guns are obsolete just like the bow and arrow.
We continue because of legalities of war to use guns. High Power fiber lasers and other weapons such as ADS are much more effective and leave little or no residue of what happened. Hypersonic weapons will change the way we fight because an army than can not hear is no longer useful to the commander. If we take the lawyers out of the battlefield and fight to end a war quickly and surgically we will better off. We need to stop fightining on the enemies rule. We need to turn the technology on and destroy the enemies.