People kept giving Don Knotts bullets
The deputy's single bullet was such a beloved running joke that fans gave him hundreds of single bullets.
While Sheriff Andy Taylor was the "Sheriff Without a Gun," Deputy Barney Fife has no such reservations. Barney's gun handling is one of the most well-known running gags on The Andy Griffith Show. He loves to flex his authority by carrying one, but since he more often ends up shooting walls, windows, or his own foot, Andy makes a strict rule that Barney is to carry only one bullet in his shirt pocket.
Of course, when the situation arose where a loaded gun would be handy, Barney starts shaking and fumbling as he tries to put his single bullet in the gun. It's just another part of what makes Barney Fife such a memorable character.
Fans loved the deputy and his single bullet, to the point where Don Knotts amassed an unusual collection.
Daniel de Visé, in his book Andy and Don: The Making of a Friendship and a Classic American TV Show, wrote about the fans who would bring Knotts a single bullet.
Actress Dodie Brown, who worked with Knotts onstage, said that fans "would line up along the hotel, three blocks, and wait in line to get an autograph from him. They would come up and say, 'I’m your best fan.' Every single person would say that. Every policeman would bring him bullets."
According to de Visé, Knotts held on to these gifts. "Don [Knotts] never knew what to do with the bullets... Hundreds of them rattled around the drawers of his Century City condo."
Sheriff Taylor would have been mighty upset if his deputy had started carrying those hundreds of gifts in his shirt pocket.