That .esp file modifies MAC-11:

          Characteristics:

- looong range
- damage 400 +
- refills action points
- faster fire rate
- almost weightless
- additional energy damage 400
- mag size: 800
- super zoom 3,5 - 5,5 in the game
- kills any target on any distance
- bullets are constantly accelerating instead of decelerating, when out of range they are reaching 1,2 dmg power
- the gun is almost not shaking
- supersonic bullets are penetrating several targets thought on one line
- expensive : 1500

                      download the original mod below:

 all credits to DOOM : http://www.nexusmods.com/fallout4/mods/10211/?