You could get a reasonable approximation of it by hanging in a harness with your feet off the ground when you fire.
Paratroopers can do that. But, you need a safe place to try it, so that bullets don't go anywhere they can cause trouble, because it is hard to aim well when your body is not braced for the recoil. Adjusting the sights on a gun to hit the point of aim is pretty dependent on how you are bracing yourself for the shot. It's that rotational effect I mentioned in the previous post.
Of course, hanging from a harness, from a fixed tower or a parachute, involves more forces than doing it in free fall or orbit, but you get the idea what the gunshot forces are tending to do. It is just that gravity will counteract it pretty quickly if you are subject to it.
Unless you can pay Elon to put you in orbit and convince him to let you open the hatch to a Dragon capsule and then fire a gun into space, you are going to just have to think your way through it instead of doing the experiment yourself.