If one considers Fallout 4 to be outside of the Fallout continuity the game.

Any help on this would be greatly appreciated. From my perspective Fallout: New Vegas and Fallout 4 are completely different games. I thought there was probably some mods overriding it (I have quite a few mods but I checked the weapon in FNVEdit and nothing was modifiying the alloy steel combat shotgun, it was only touched by the main TTW esm) I know what needs to be done (add the alloy steel combat shotgun to the perk lists for shotgun surgeon and and stay back) but I have no knowledge of modding in new vegas other than installing mods and maybe changing a few simple values in FNVEdit (DT, Damage, Ammo cap stuff like that). I have a feeling that the perks arent applied to the shotgun so thats why its so weak towards the super mutants. So after I completed anchorage I went in the storage room and got the alloy steel combat shotgun (10008AF3) and was excited about it only to realize it was useless against super mutants (playing on very hard) even though I had shotgun surgeon and stay back perks.

Fallout new vegas combat shotgun