Doug Henwood wrote:
>
> Chip Berlet wrote:
>
> Maybe, to use a phrase
> George Soros almost used at the CFR before censoring himself, they've
> shot their wad.
>
You and Soros are both assuming that the phrase was/is literal when applied to sexual emission. I doubt that, but I don't know what the original might have been. A guess (this is called folk etymology, and it is as apt to be in error as a non-biologist trying to defend a trait as an adaptation): Originally it referred to having run out of musket balls and having nothing else to fire but the wadding material which held in the powder. Then it was extended to other areas as metaphor (and not even necessarily _first_ sexual metaphor)???
Carrol
The OED isn't conclusive, but suggests that its earliest slang usage was non-sexual:
4. a. A plug of tow, cloth, etc., a disk of felt or cardboard, to retain the powder and shot in position in charging a gun or cartridge.
1667 Phil. Trans. II. 476 Another [experiment]..is a Wooden Tampion..hollow'd towards the Bullet,..and..hollow likewise towards the Powder, and serving instead of a Wadd. 1669 STURMY Mariner's Mag. V. xii. 68 Put the Powder home gently, and after put in a good Wad..; then put in the Shot.., and after him another Wad. 1769 FALCONER Dict. Marine (1780), Wad, a quantity of old rope~yarns, hay, &c. rolled firmly together into the form of a ball, and used to confine the shot or shell..in the breech of a piece of artillery. 1856 ‘STONEHENGE’ Brit. Sports I. I. ii. §5. 24 After using the powder-flask..drive down..a single piece of wadding; then pour in the charge of shot, drive down another wad, [etc.]. 1862 F. A. GRIFFITHS Artil. Man. (ed. 9) 112 No. 5 serves No. 3 with projectiles, wads, if necessary, and traverses. 1879 Cassell's Techn. Educ. I. 194/1 The escape of gas was prevented by means of a felt wad attached to the back of the cartridge. 1881 GREENER Gun 300 Wads are punched out of sheets of various materials by cutters fixed in a press. Those most commonly used are made of felts, cardboard, or jute. 1890 D. DAVIDSON Mem. Long Life ii. 34 We..rowed too closely past the Victory as she was firing her royal salute, and one of her wads just cleared our heads.
b. In fig. phr. to shoot one's wad, to do all that one can do. Cf. to have shot one's bolt s.v. SHOOT v. 21b. colloq. (chiefly U.S.).