Yes, I'm serious.
Since air guns are considered a firearm, I had to get pistol & rifle purchase permits to buy air guns. This involved a background investigation by the state police which took about 3 months. When I got the purchase permits, I found that they were only good for the purchase...
I may be moving back to NJ in a couple of months. Therefore, I'd like to sell the air (pellet) pistols I purchased while in MD. Is it legal, in MD, to sell air guns at a Garage Sale?