Maybe a bit un-cannonistic, but it works on doors and locks, also gives electric shocks randomly and can reprogram roller mines(Few seconds then explode),turrets,cameras.
The tool can shock the user, and maybe explode.
As this is a plugin, you will have to download this model zip from: https://github.com/trurascalz/clockworkplugins/raw/master/hl2rp/empgun/models.zip
Then unzip that to your /garrysmod/models directory. (so the weapons folder goes in /models)
If model doesn't download you need to resouce.addfile it in lua/autorun/server/afilename.lu