End of the Line

From publisher blurb:

End of the Line: Enough is enough. The Outlaws are getting on a bit these days, they've lost too many friends over the years to a hail of gunfire, and the Law's been doggin' them ever closer every year – they want outta the life. But they don't want to end their days coughing up their lungs in some mine or factory somewheres, neither, so they decide to quit outlawin' after making one last big score. And the big score they hit upon making is truly big: the army pay train. It's maybe the richest stash of cash any wheres in the West. But, of course, it's also the most heavily guarded.