Cost = 4200$
Rank = 5
Ammo = 30 (Instead of 15).
This is to combat the insane rate at which ammunition is used, it can be very annoying when using the skorpion.
I hope adding more ammunition wouldnt be too Overpowered.
EDIT:
I decided to add an alternative attachment based on WorkLoks point that its the firerate which is the issue
Attachment: Semi-Auto Trigger
Cost = 3000$
Rank =5
Effect: Skorpion becomes a semi-automatic gun, but goes (Pretty much) as fast as you can click. This would definetly help out the beginners who just purchased the weapon.