Rail Gun

The Rail Gun is a new weapon appearing in the enhanced version of Grand Theft Auto V; the weapon is exclusively available to those returning to GTA V from the original PS3 or Xbox360 versions.

Design and Performance
The weapon appears to be high-tech and fires inert rounds at high velocity.

According to IGN.com, one shot is enough to destroy a car. It will probably kill pedestrians in one shot.

According to computerandvideogames.com, rounds don't cause damage if they miss or land near the target.

The shot seems to reach its target instantly. However rate of fire is very poor, taking several seconds between shots to cool the weapon, and lacks of splash damage.

As a result this weapon seems very effective at taking down helicopters and destroying vehicles, but in return seems lame against enemies on foot.

Customization
TBA

Trivia

 * A rail gun is a weapon that fires dense metallic rounds at velocities higher than the speed of sound using electromagnetism. As such, it has incredible range and accuracy in addition to massive kinetic energy. However, current rail guns are in the prototype phase and due to a myriad of issues, such as power generation and heat dissipation are limited in size and portability to fixed (usually naval) mountings. Portable railguns do not exist outside of theoretical models.
 * This, along with the Jetpack, are prototype military devices featured in the GTA series.
 * The explosive effect is not caused by the tipe of the round, but instead by the huge kinetic energy: it's unlikely that a rail gun round will cause heavy damage through splash damage. Direct hits cause massive damage like explosive rounds, but the explosion effect is usually caused by the gases that are caught in the projectile trajectory, which get enough heat from the air friction to become plasma.