Bandit Medicine
Here are some photos of me with my under-the-bed shotgun, a Winchester 1300 pistol grip. The front grip allows me to carry it with my left hand, tucked under my armpit, right hand free.
Shooting it without risk of hurting yourself requires a locked left elbow and the front grip pressed firmly into the web of the front hand. Click on the image for a higher-resolution version (71K, 1167x566 pixels).
Egads! It reminds me of that picture of Chuck Schumer with the Uzi (later... actually it was a TEC-9).