While I am no expert, I spent a fair amount of time looking for this. I'm not 100% it represents a "real" weapon, perhaps a movie custom?
Obviously it's a rear action, or bullpup, design. I searched for both terms.
It gives the appearance of being a sniper rifle, but the magazine looks like a (relatively) small round. It also seems to imply automatic action, rather than bolt action, so not sure how that figures into a sniper weapon.
It also turns out that rear action custom conversions are a real thing, so I tried searching for it as a "regular" action weapon as well. No luck.
Usually, the grip will give away the manufacturer, but the closest match I found was still not correct.
Again, no way I am I a weapons expert. Perhaps someone more knowledgeable will weigh in.
Cool model though!