Puncheon (barrel)

Capacities of wine casks were formerly measured and standardised according to a specific system of English units. The various units were historically defined in terms of the wine gallon so varied according to the definition of the gallon until the adoption of the Queen Anne wine gallon in 1707. In the United Kingdom and its colonies the units were redefined with the introduction of the imperial system whilst the Queen Anne wine gallon was adopted as the standard US liquid gallon.

The major wine producing countries use barrels extensively and have developed standards at variance with the traditional English volumes are commonly used in the wine and wine cooperage industries. Examples include a hogshead of 300 L (66 imp gal; 79 US gal), a barrique of 220 L (48 imp gal; 58 US gal) (Bordeaux), a barrel of 225 L (49 imp gal; 59 US gal) (Australia), a barrel of 230 L (51 imp gal; 61 US gal) (Burgundy) and a puncheon of 465 L (102 imp gal; 123 US gal).

The tun (Old English: tunne, Latin: tunellus, Middle Latin: tunna) is an English unit of liquid volume (not weight), used for measuring wine, oil or honey. Typically a large vat or vessel, most often holding 252 wine gallons, but occasionally other sizes (e.g. 256, 240 and 208 gallons) were also used.

In one example from 1507, a tun is defined as 240 gallons.

Early Modern English: "He that ys a gawner owght to understonde there ys in a tunne lx systerns and every systern ys iiii galons be yt wyne or oylle."
Translation: "He that is a gauger ought to understand that there is in a tunne 60 sesters, and every sester is 4 gallons, be it wine or oil."

...
Wikipedia