Go to Abilities, make a NEW custom ability, then for the base ability, use item armor bonus, then...
Remove ALL the bonus's
- Go to attachment points
- Type Weapon as the first string, and right as the second string
- Find the Target variable, and put the weapon model as the target (you must import it and restart the editor first)
- Now, find the marine unit you want to hold the weapon, and give him that ability as a natural ability
Now hes holding it, for the Effects/Sounds you have to use triggers
- Go to triggers
- New trigger
- Events - A unit is attacked
- Conditions - Attacking Unit equal to (Unit you want the effect to be attached to)
- Actions - Special Effect - play special effect attached to unit using (wanted effect)
- Actions - Sounds - play sound on unit using (wanted sound)
To find sounds for these guns, I recommend opening the map Curse of the Lost City 4.0 from epic war and using the gun sounds.