The number of DGUs is difficult to determine. Most will not be reported. For the sake of argument, I typically use the lower numbers. But even the lower numbers provide plenty of evidence of the worth of privately owned firearms.
Problem is you don't have verified, third party evidence of DGU's. What you do have is anecdotal stories of crimes stopped by people who have some sort of point to prove about gun ownership.
For instance. How many crimes have you stopped using your gun? How many of your friends have had to use their guns to stop crime being committed against them? I take it you know a lot of gun owners, so there should be more than a couple of stories to go by.
I had a person beating on my front door about 22, 23 years ago. I went to the door with gun in hand because I didn't know who was banging on my door. Turns out, they had wrecked their car and needed help.
Was that a DGU because I had my gun in hand? Just in case? I was prepared to be offensive.
I wouldn't call what I did a defensive gun use. Would you? I would call it being prudent and prepared to be offensive should the need arise. Best defense a good offense and all that shit. Why isn't there an offensive gun use category? One poster was saying that he had stopped robberies on himself by simply showing his gun. Now how he knew that he was showing his gun to a robber, I don't know. Sounded like offensive gun use to me.
Better story. My BIL was having trouble evicting a tenant. He went to the house with his gun in a shoulder holster. At some point he showed the gun. The person he was arguing with went in the house and came back with his AR15 and pointed it at my BIL's head. My BIL left as soon as he could. Now there is a case of DGU for the bad guys (evicted for drug dealing). Do those count in the DGU stats? I would say they must to support 2 million DGU's.