Judge advocate Jeff Blackett told Danny Nightingale, who wore his SAS uniform in the courtroom, that his stories about how the gun came to be in his room "lacked credibility".
But he said there were "exceptional circumstances" that allowed the court to suspend the sentence "because of your exceptional character".
The judge also said that "criticism of the prosecution and the Army is unmerited and totally without foundation".
We understand how difficult these proceedings have been for you and your family. However, you have brought much of that anguish upon yourself and your public assertions that you are scapegoat or the victim of some wider political agenda is absolute nonsense.
You are simply someone against whom there was a strong prima facie case of serious wrongdoing and, given the dangers to society caused by illegal firearms and their misuse, it was in the public interest to prosecute you.
You have now had a fair trial before a civilian judge and an independent and impartial board.