So after many dreadful and sweaty (not really) research I have finally found what I was searching for (lol yk 5 minutes). What resembles a railgun most is a gravigun. But as far as I understand they are rare as f***. If that is no problem then I have made the CS. Also you said power level is quite high, and I would also be an Enforcer, so I took the luxury as a Warhammer 40K analphabet to make an equipment set that fits me the best. This means it might be REALLY OP.

[hider=CS]
Name: Robert "DOA" Williams
Race: Human
Gender: Male
Age: 32
Class: Mercenary
Equipment & Weapon: Gravi SMG(on arm), Plasteel Shield (folds into the wristplates), Power Maul, Carapace Armour
Traits: Robert is very strong and quick, but when it comes to converstaion or alcohol he just doesn't know the limits (eg. rude and alcoholist)
Biography: Robert grew up on an avergae hive planet. When he was 16 he joined a crime organisation and managed to get into the higher parts. After someone threw em up he escaped the planet and joined an elite mercenary squad. He fought with them for 10 years, tanking them from damage, the first one to jump into a fight. This is why they nicknamed him DOA. But on one unlucky day, his whole team was murdered and even he could barely escaped. He kept his equipment, and has been doing bounty hunting since.
Appearance Description: Him but more badass (obviously)
[img]http://i.imgur.com/vSQiCav.jpg[/img]
 [/hider]