Solid as a rock - Caldwell The Rock Deluxe Shooting Rest and Rear Bag Combo

There's a reason it's called The Rock. This rest is solid and has enough weight to stay where you put it so you can duplicate shots without having to reset anything. With the individual leg adjustments and the main height adjustment you can get setup easily on any range. I've used it to site in my crossbow as well and multiple rifles with no issues and it makes a day of shooting that much more enjoyable.
It's also great for the wife and grand-kids, having a steady rest helps them build confidence and has greatly improved their accuracy.
As others have noted the rear bag is not an ideal support for the butt stock but it's included in the combo package at a price-point comparable to the rest alone.