Andrew Brown thought he could goad police into shooting him when he took the bright yellow weapon, which was obviously fake, to the fields at Chuter Ede in South Shields.
Newcastle Crown Court heard the 29-year-old telephoned police and said: "I'm Andrew Brown, I'm going to be on Chuter Ede field and I've got a loaded gun".
When officers arrived at the house he had made the call from, Brown came back and told them the toy weapon was abandoned in the field.
Prosecutor John Crawford told the court: "On arrest Mr Brown stated it was just a yellow plastic BB gun, it's next to the football cages at Chuter Ede park.
"Officers attended and located the bright yellow plastic BB gun."
Brown, of Chesterton Road, South Shields, admitted possessing an imitation firearm in a public place.
Judge Robert Adams said "we are talking about a yellow plastic gun here" and that the weapon "doesn't seem to me to resemble a proper firearm" and added no distress was caused by him being armed with it.
Judge Adams said the most serious aspect of Brown's behaviour was two common assaults he carried out on his pregnant partner in March and April, both this year.
During the first attack Brown grabbed a shower rail and deliberately caused it to fall down onto the woman while she was in the shower, causing injuries to her leg.
Brown lashed out during the second confrontation but the victim managed to block his blow before he caused over £700 worth of damage to property at her home.
Brown admitted two offences of common assault, criminal damage and breach of a suspended sentence in relation to the violence.
The court heard in February 2020 he had been given a nine-month jail term, suspended for two years, for headbutting a former partner and causing damage to her home.
Judge Adams jailed Brown for a total of ten months, with a two-year restraining order to keep him away from the pregnant victim, and said "he doesn't seem to have learned his lesson".
Nicholas Lane, defending, said Brown was in a "fragile mental state" at the time and added; "He briefly thought the police would attend and he would be able to goad them into shooting him."
Mr Lane said Brown has family support and employment available to him.
Mr Lane added: "He assures the court there will be no repeat of this behaviour."