If you want to make enemies, try to change something.
People use Lasers and Plasmas. Next update will bring improvements to 7.62mm which should see the FN FAL and m60 used.The only other place 7.62mm could be allowed to be crafted in would be NCR/Rangers, if and when we put them in the game.
Depends how they are implemented. Nothing about NCR is finalized.If it were purely down to me I would have 1 7.62mm machine somewhere and let the 2 NPC factions fight over it.
I think 7.62mm weapons are pretty decent now. We shall see.
Depends if we are talking in the era of LSW dropping everywhere or not, considering they are not craftable.