you could try turning while doing brush knee and push:
turn counter-clockwise, your left lower hand brushes the gun-arm away as you pivot, the right palm strikes to the chin. You can lock his arm and continue to a take-down.
Turning the other way, clockwise, the right hand brushes the gun arm, and as you step around, it locks the arm, while the left hand is under the jaw and locks the neck. You can continue turning into a take-down as well, or grab the wrist, and do an outward wrist lock and throw, as in jiu-jutsu's koto-geashi.
"My Gung-Fu may not be Your Gung-Fu.
Gwok-Si, Gwok-Faht"
"I will not be part of the generation
that killed Kung-Fu."
....step.