On one hand I don't think they want a lot of gunsmithing type stuff going on, When you're in the range. But on the other hand, they don't really watch the cameras that hard either. So you may be able to get away with your gun vise and sand bag.
I dont think they would like any "smithing" on the line, so I don't know about a gun vise. But if it were for shooting, they probably wouldn't care. You can certainly site in and make adjustments. A sand bag should certainly be fine. Their most important rule is controlling your weapon. Practice safety and hit the backstop, and they're cool.
Thanks! Your answer is awaiting moderation.