His foolish statements provided his opponents with more 'ammunition' to use against him in the campaign.
She had the 'ammunition' to prove her case. [=she had the evidence she needed to prove her case]
The troops were supplied with weapons and 'ammunition'.
(..) - I love you. - I love you too. You need some help? Now that you mention it. We'll take your weapons, your car key, your ammunitions. And if you got it, sugarless gum. What the fuck. Wa.. Wait, why are you guys doing it? (..)2009 Zombieland