I have to say, I agree with Rockwolf and GM, it does look like the Accuracy International Covert model, which is a version of the Artic Warfare model modified to fold and fit into a suitcase. I'm not sure where the Remington that 4570 mentioned comes into this, as I can't find a version that matches up. Here's some pics which pretty much confirm what RW and GM have said and match up pretty much perfectly with the screencaps:
Definitely seems to be this one, and it kinda figures considering the nature of the show, which tends to use modern and more unusual weaponry, as the hero is a former spy.