In Texas, it is illegal...
for a fired bullet to cross a property line.
The solution appears to be putting your "shooting house" on the property line, with the fence at your back. That way, all shots, taken by you, are away from the neighboring tract of land. Shooting from an elevated shooting position should also create an angle that ensures the bullet will imbed in the ground, rather than richochet across our land, possibly endangering others.
Of course your neighbor may not understand your intent, but if you explain that it is for HIS safety, he may get the idea.
You might even mention to him that he should put his stand on the fence, too, with the fence at his back. For YOUR safety. Maybe he will, maybe he won't.