The JS-53 Uranium Slug Accelerator is the standard issue sniper rifle for marksman-class soldiers of the Nexus.
It is pump action and has a very slow rate but does have deadly pinpoint accuracy and a pretty good damage output. However, it is still not very good for stealth for the brightness of the uranium slugs as well the streak they leave behind easily points out the sniper's location. The uranium slugs fired by this handy-ass weapon can travel through very tough metals even the plating of the UA's BT-253 Main Battle Tank.
The primary fire launches a single uranium slugs at very fast speeds while its secondary fire mode builds of the heat and power of the weapon, soon firing the uranium slug at an even faster speed directly afterwards. This does more damage and has better penetration than the primary fire but of course the charge does take a second or two.