https://www.youtube.com/watch?v=1qUFEoZBPFQ
If you want it to look real just find one that suits your ascetic taste... AND shoots .177bb to begin with.
You might have more success asking a BB gun forum to help as it is their specialty.
On a side note... Can I convert a Mitsubishi Lancer ES to an Evo that runs on diesel and floats?
Would a 50 cal mounted though the sunroof be awesome or overkill?
Would I need a LSD or could I get away with a live rear axle?
So far for this project I've got two hammers and some rum...