IA-AR18/A Assault Rifle PREVIEW

EDIT 2015-05-08: Only the finishing touches left. I finally made a good design for the optical sight, which would not be too large for a standard issue rifle. Oh, and I just realized I have not changed the name from "S" to "A".

EDIT 2015-07-25: Prepared the model to be able to take it apart. The scope is quite a bit larger now. Interior for the magazine compartment is almost done! See other upload for exploded view.

My first real attempt to make a handheld weapon, and actually finish it. I've taken inspiration from the rifle used in the movie Oblivion, as I really liked the looks of that one. I try to keep it inspirational only, many things are different. The magazine for example, is on top of the gun, under the scope. If any of you have played Deus Ex: Human Revolution and have used the assault rifle, the reload mechanism is about the same. The stock is also completely different, as it's much thinner and more customizable.

Infinity Arms AR18/A Assault Rifle.

Switch to exploded view.

The first rifle in the IGF to use newly developed railgun technology for small arms. It is loaded with ammunition from the top, and a powerful battery from the bottom. Since the projectiles have no need for gunpowder, they are shaved off the magazine to slugs the size of 5x15mm inside the weapon. The weight and muzzle velocity give these slugs a stopping power more than equal than that of a traditional round. A single magazine can give about 1500 slugs with this technology. The battery, however, can only supply enough power for up to 120 rounds. Soldiers with support roles can be equipped and connected to external batteries which provide more than enough power to supply a normal firefight.

The second thing the user has to worry about is heat. The rifle has a built-in advanced cooling system, but it can only assist to a certain degree. Under normal conditions, heat shouldn't be a problem. In case of an overheating rifle, the user can switch the heatsink and cooling system module. When the module has cooled down, it can then be used again.

Specifications:
Caliber: 5x15mm
Muzzle velocity: 1,900 m/s
Kinetic energy: 4,093 J
Effective range: 900m
Maximum range: 1,250m

Magazine size: 1,500 slugs
Battery power: ~120 rounds
Heatsink: 
~320 rounds (non-stop firing, auto)
~500 rounds (battle condition, burst fire)
~800 rounds (medium battle condition, burst fire)
∞ rounds (light battle condition, single fire)