unlimited 與 infinitive

unlimited (adjective) = as much or as many as possible; not limited in any way 無限的, 無數的

infinitive (noun) = the basic form of a verb (grammar) 不定詞, 不定式

In English, this form of the verb together with the word ‘to’ in front of it is usually called a to-infinitive, and the verb form on its own is usually called a bare infinitive.

這兩個字不同的解釋, 而且一個是 noun, 一個是 adjective

unlimited 與 infinitive 是不可能互換通用

ammo (informal) 是 ammunition = 軍火,彈藥

“infinitive ammo” doesn’t make sense.

Just a suggestion
想是 infinite 這個字, 不是 infinitive

infinite (adjective) = without limit, without end 無窮的,無限的

我最近形容一個知識長 a man of infinite patience

相信 infinite ammo 和 unlimited ammo 意思相同

再 check “The Cambridge Thesaurus of American English” by W.D. Lutz
infinite = unlimited

再 check 網上, 有 phrase, "infinite ammo"

https://www.youtube.com/user/infiniteammoinc