Get two real shooting bags like an Armageddon Gear Gamechanger Shemedium and a pint sized w/ GetLite fill and place one in the window and one on the top of your chair back turned around backwards.
Heavy sand media in the bag is slightly more stable if the bags will be dedicated to a single shooting house but gets heavy transporting to multiple houses.

Find a (non-swivel) chair that has a back close to the correct height to support the buttstock of the rifle in shooting position. Turn chair around and sit backyards in it and use your support hand to manipulate the bag underneath the buttstock on top of the chair back.

Simple setup and solid as a shooting bench with minimal practice.

The cheap Lifetime brand folding chairs from Walmart work well for this method.

Like this- https://youtu.be/uFqGVuop_Q4


You're only as good as your worst shot-