I seriously doubt you will see a major paradigm shif in personal weaponry in the first half of this century. Possibly for the entire century.
Modern firearms have certain drawbacks, but the idea of an energy beam weapon is still science fiction. Now dont go posting some story about some experiment or idea - certainly ray guns are possible I just do not think them practical.
Anytime you have to charge a power source to use a weapon, that seems like you are asking for complications.
Also - rail guns have serious EMP issues, not to mention the fact that over penetration would be INSANE.
Rail guns were considered for missile interception weaponry as the speed of the projectile made it feasable.
You simply do not need a handgun or rifle that shoots a metal slug at 10,000-20,000 fps.
Also - given the current climate, low tech weapons are going to be preferred. Too many people would we weirded out by electronic weapons.