For Stan R. Mitchell of Oak Ridge, Tennessee, this concept turned into his novel Sold Out. Not only is Stan a former Marine, he has a love of books like Stephen Hunter's Point of Impact and Pale Horse Coming, and Sold Out could easily have been another book in the Bob Lee Swagger series of Hunter's novels. The story follows Nick Woods, a former Marine Corps scout-sniper who has found himself a life away from violence and bloodshed, although he's still more than a little paranoid, and definitely damaged goods. But when a top-secret assignment from his USMC days bubbles to the surface, exposed to the world's media, the architects of that assignment - and the failed cover-up that resulted in the death of Nick's spotter - move to take Nick out of the picture.
I won't go into too many spoilers, but let's just say, they make Nick angry. Really angry. Like, nothing to lose, no reason to live, from Hell's heart I stab at thee angry. So Nick goes on a crusade of vengeance and retribution to put paid to those who've made his life a ruin.
And when Marine scout-snipers go on crusades of vengeance and retribution against you...you're pretty much fucked.
Sold Out is a very fast, action-packed novel. There's a lot of chapter breaks as we shift perspective between Nick and his reluctant partner Allan, the disgraced reporter who inadvertently ruined Nick's life, as well as the bad guys trying to hunt Nick and Allen down. Some people dislike constant shifts of POV, but here I think it works very well - I consider it a more "cinematic" style of writing, where the camera and story line cuts back and forth between both sides of the conflict. It isn't the sort of technique that works great in a "thriller", where the motives and movements of the antagonist need to be shrouded in mystery, but in a more straight-up action piece, I think it's fine.
Speaking of action, Stan writes the fight sequences quite well. There aren't many big running gun battles, but as the story really focuses on one guy - a sniper no less - against a small army, a "running gun battle" would probably end in disaster for the protagonist. However, Stan deftly handles the tension and the pacing, making every battle a page-turner.
All in all, if you're a fan of Stephen Hunter's books, and "wronged man seeks bloody retribution against powerful asshats who deserve to die" stories in general, you're going to really enjoy Sold Out. Highly recommended.