An idiom involving walking on a branch

Question

I am reasonably certain that once, glancing over a long list of English idioms, I saw an idiom that I now remember as "walk on a branch" and cannot find anywhere, so my memory must be wrong.

The listed meaning was "to give it a long shot", "to make a not-necessarily-educated guess", the implication being that it is similar to stepping on a tree's branch that may crack under you foot.

I cannot look this idiom up anywhere, to the point where I am starting to doubt it even existed.

It was not:

• walk on eggshells
• walk on thin ice
• walk the plank

Does it exist, and if so, what is it?

Answer 1

I think you are looking for go out on a limb.

As freedictionary.com puts it:

To do or say something that lacks evidence or support.

Or, as Wiktionary says:

• (idiomatic) To take a risk.
• (idiomatic) To hazard a guess

KnowYourPhrase.com agrees almost completely with Wiktionary:

1. Putting yourself in a risky or precarious situation in order to help someone.

2. Taking a wild guess at something or expressing an opinion that might not be shared by others.