jump the gun

Idioms  

1. Start doing something too soon, act too hastily. For example, The local weather bureau jumped the gun on predicting a storm; it didn't happen for another two days. This expression alludes to starting a race before the starter's gun has gone off, and supplants the earlier beat the pistol, which dates from about 1900. [Mid-1900s]

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Example Sentences

Further questions were raised last week when the British military seemed to jump the gun in announcing Kate would attend a Trooping the Color ceremony in June, apparently without consulting palace officials.

From Seattle Times

"We do not want to jump the gun on an announcement but I think it is quite likely that it will be a significant investment in our relationship with India," he told reporters.

From BBC

Okay, I do want to jump the gun because I’m certain of what we’re seeing.

From Washington Post

“If he’s going to disrupt the proceedings, as long as she doesn’t jump the gun, which in my view she has not, there shouldn’t be any issue,” Grieve said.

From Washington Times

“When you jump the gun with no evidence, it makes it worse. … We don’t know what caused this shooting.”

From Washington Post