What's the origin of metaphor "to give someone ammo"? [closed]

In last decade I often encounter this phrase used as "giving the opponent an argument in debate" while discussing an unfolding drama or conflict.

While I understand the meaning, I wonder how it come to be? Is it just a colloquial metaphor coming from idea that you need "ammo" to shoot or it got a literary source. The problem arose during performing formal translation of text, which should have been proof-readed. Proof-reader used local offically approved dictionary which contained only one meaning for "ammo": supplies for firearms or artillery. In result figurative translation was refused as illegal. It could be accepted if errata to dictionary would be approved, but it cannot contain slang (don't ask me why).

If only "ammo" used in such meaning, the whole phrase might be slang or argo. If ammunition (literary form) got such meaning, my question is what proof of such could be used, with a source. The problem is that translation requires formal proof acceptable by regulation authority.

Oxford Dictionary of English, Third Edition, page 52:

ammunition (noun) [mass noun] a supply or quantity of bullets and shells. considerations that can be used to support one's case in debate: these figures provide ammunition to the argument for more resources.

1645 quote for figurative use as in OP question in Oxford English Dictionary (First Edition, 1888).

This Spirituall Ammunition [sic] shall sufficiently furnish the soul for her encounter with her last enemy.

Adding to the existing contributions, to give someone ammo is of course a war metaphor. War metaphors are a common and rich source of imagery.

I can, for example, imagine some politician saying something like:

• COVID-19 has now launched its attack on home territory.
• The region is under fire from the virus.
• Returning to normalcy following lockdown will be an uphill battle.

and so on.

More war metaphors: http://knowgramming.com/war_metaphors.htm

Ammo= Ammunition.

Ammunition= 1.a supply of bullets, shells, bombs, etc. Ex: an explosion at an ammunition dump.

2.information that can be used in trying to win an argument. Ex: the letter gave her all the ammunitions she needed.

Entries related to ammunition. 1.ammo 2.munition.

Ammunition, often called ammo, comes from the French word la munition.At first it meant all items used for war. This was from the Latin word munire (to provide).

"To give someone ammo" or "to give someone ammunition" means to say to someone something which he can use against you, or to do something.