When boozed-up plasterer Jamie Harrison-Ring found a toy gun he thought it would be funny to take it into his local shop, a court heard.
A member of staff at Costcutter in Newton Road, Twerton, fled as Harrison-Ring came in with the "weapon" tucked under his jacket.
In a bizarre, brief episode he said "No f-ing CCTV" and walked out.
Whatever he was carrying was not recovered.
The 26-year-old, of Newton Road, Twerton, pleaded guilty to possessing an imitation firearm on January 30.
Judge Julian Lambert adjourned his case, pending mental health assessment, for sentencing on a date to be fixed.
Matthew Jackson, prosecuting, told Bristol Crown Court Harrison-Ring walked into the shop with what appeared to be a "long-barrelled gun, about two to three feet long" tucked under his jacket.
Witnesses said he appeared to be looking for someone before he made the comment about no CCTV and walked out.
Mr Jackson said: "A staff member left the shop due to their fear and returned home.
"The weapon was down by his side at all times.
"He was a regular customer of the store and he was found by police, driving.
"He was reported missing by his partner.
"On the day he had been drinking quite heavily."
It was conceded Harrison-Ring had not pointed the object at anyone.
Mr Jackson added: "He says he found it outside in the street.
"He thought it may be funny to take it in."
Emily Evans, defending, said: "He's very keen to ensure the court is told it was a child's toy he walked into the store with.
"He appreciates other people may not have appreciated that at the time."
Miss Evans said her client recognised he needs to have some intervention with appropriate services.
