In a previous post (How many kilderkins in a hogshead) it states:
“The standardised measurements continued to be the subject of later statutes. In 1423 an Act of Parliament first standardised the hogshead, though the volume varied by locality and content. By 28 Henry VIII, cap. 14 it is re-enacted that the tun of wine should contain 252 gallons, a butt of Malmsey 126 gallons, a pipe 126 gallons, a tercian or puncheon 84 gallons, a hogshead 63 gallons, a tierce 41 gallons, a barrel 31.5 gallons, a rundlet 18.5 gallons.
So half a tun is a butt, or perhaps a pipe; a third of a tun is a tercian, or puncheon; quarter of a tun is a hogshead; a barrel is an eighth. Who knows how a tierce (at just a little more than a sixth) or a rundlet (at nearly a thirteenth) came to be decided on.”
Today, while working on transcription of a book of accounts of 1619 I found the following:
“It[em] For a Rinlett of Clarett wyne containing vj  gallons v  pintes at ijs [2s] the gallon”
And a quick search online led me to : Rinlett, runlet — a cask or vessel of varying capacity (N.E.D.)
So is a ‘rinlett’ not the same as a ‘rundlet’ or was the barrel was only 1/3 full?
Given that in the same set of accounts the Clerk of Kensington was paid 4 shillings for a quarter of a year’s wages, it is to be hoped that the claret wine at 2s the gallon was good quality stuff.