This is something I've been working on today: a railgun, which I call TITAN.
For those of you who don't know, a railgun is an experimental firearm concept which uses electrically charged 'rails' to propel a projectile at colossal speeds, far greater than a regular bullet. Railguns have yet to make any reliable appearance in reality, but they often show themselves in popular fiction, a notable example being the Metal Gear series.
TITAN is my own design, though I have been inspired by many sources. Having not seen many man-portable railgun designs here on MOCpages, I decided to have a go at creating one. Using ideas from the real and fictional worlds, TITAN was born. The main body was partially influenced by the futuristic appearance of the FN F2000 rifle, as was the bullpup layout. I took the rail design from Metal Gear REX, and a few Google Image searches. The spare rounds on the side of the weapon were inspired by a common shotgun technique of ammunition storage.
Then, I added some features I figure would be seen on a railgun of this fashion. Since railguns are capable of launching projectiles at massive speeds, I thought that they could potentially fill a sniper role. So, I added the scope. Underneath the scope's rear, I added some coloured studs to serve as charge level indicators, since almost all railguns in pop-fiction require time to charge up the rails. Also, since projectiles are not bullets, but pure chunks of metal, the weapon cannot operate like a conventional firearm and use blowback or gas-operated priciples. So, I added a manual bolt, which would be used to cycle the rounds, much like a bolt-action rifle.
So there you have it. I will add the LDD file to this MOC for anyone who wishes to use/improve my design. Please comment with any feedback you may have!