This mod is not created by me but one of my friends who I talked with a lot over this project as we both wanted to make a NERF pulse rifle from Aliens. He completed his before mine which when I am finished I will also post.
Note: there is no instructions at this time to make this blaster, you may infer on what mods were done but a step by step instruction is not ready at this time and possibly will never be ready.
He made this using:
nerf LongShot Rail,
Nerf LSFG (Longshot front gun),
nerf raider stock
and other materials.