The AK-47 is the most lethal gun because you can learn how to use it in one hour or less. It is also the most produced weapon in the world.
Yes the ray gun is lethal, the ray gun is one of the most powerful guns in nazi zombies
Any gun is capable of being lethal. If you wanted a "most lethal", maybe the 155mm howitzer, which is capable of launching tactical battlefield nuclear nuke.
Any metallic bullet fired from a gun can be lethal. Pistol ammo is not designed for different degrees of lethality, but is designed for effectiveness in stopping and attacker. That is likely to be a jacketed hollowpoint cartridge.
A Ray Gun is commonly mistaken for its real life counterpart, the Water Gun. A Water Gun can be an extremely lethal weapon when in your command. Though it is lethal, there have been many misuses of the gun due to reckless children.
9mm beretta
Most of your "less lethal" (none are billed as non-lethal anymore) projectiles are intended to be fired through a standard firearm. You might, however, be thinking of a gas pistol, which is incapable of firing live ammunition.
Laws of lethal force vary by state, but, in most states, the answer is going to be no, unless an imminent threat exists.
A short barreled shotgun is not necessarily "more lethal" than a long barreled shotgun. However, it is more readily concealable, and has lost most of its usefulness as a sporting (hunting) weapon.
it shoots a lot of bullets in a short time
Gun stores which also cater to non-lethal/less lethal defence needs will typically carry them, and you might find them at military surplus stores and the like. You can also order them online.
The question is a bit moot. All guns are capable of being lethal.
Given the right set of circumstances, yes.