So I have been using the Overseer's Guardian for a bit and it is an amazing gun, like the damage is amazing. Recently I was thinking to craft a better receiver on it to do more damage, it gives it some thing like 50 plus more damage.

So I did the upgrade and started using it and I immediately noticed that when I shoot that the legendary perk on it does not work at all, the perk is that it shoots an additional projectile. I have tried shooting the gun around 100 times and nothing, it just single fires.

Anyone know why it does this or a fix to it?

It's shooting the extra projectile. Just configure a regular combat rifle with the same mods and see the damage difference for yourself in combat.

Thing is before, you can definitely tell that it shoots twice but after the change it shoots once per shot. I can definitely tell the difference. But I will test the damage difference tomorrow after work.