Arsenal inventory (4)
I believe the answer is:
ammo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">arsenal inventory</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ammo that I've seen before include "Bullets and bombs, etc (abbr)" , "Bullet" , "Bullets, say, in short" , "Bullets (sl.)" , "Slugs perhaps" .)