This mod is intended, eventually for Fallout Liberty once it can be ported to the Fallout 4 Engine (I believe), and as such, it is planned to mave many customizations and mods. As of Fallout new vegas, it has 3 (the games limit)

Shortened Barrel (Reduced Weight)

Scope (Adds Scope)

Advanced Transformer (Increases ammo cap.)

It does much more damage than the standard laser rifle, but fires slower, is heavier, and holds less ammo. It doesn't look too great, but it's intended for PBR, so that should look better, and honestly, I started work morning today, so it was fairly quick :P
It can be found in Old Mormon Fort.