It makes sense if you know that the rifle was purchased as a throw down rifle at General Walker's. Lee and George wanted the rifle to be found by the police after the hoax "attempt" to shoot Walker. But they didn't want it found until Lee was out of the country and on his way to Cuba.
It makes sense if you know that
Walt fabricated a story that the rifle was purchased as a throw down rifle at General Walker's.
There, I fixed it for you.