Green’s Dictionary of Slang

ammunition leg n.

a wooden leg.

[1649		‘Ormonde’s Breakfast’ in Carpenter Verse in English from Tudor & Stuart Eng. (2003) 284: Reader, This is bur private Soliders chat, / As rough, as is his Ammunition hat].
1838		Bentley’s Misc 588: ‘Why, what’s the harm of an ammunition leg?’ said Joe. ‘Lord love your heart! you should see the wooden pins as they have piled up in tiers at Greenidge.’.
1843		Devizes & Wilts. Gaz. 26 Jan. 4/1: His ammunition-leg had received a more than usual polish of beeswax, and there he stood.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1890–1904		Farmer & Henley Sl. and Its Analogues.