27 CFR § 5.47a - Metric standards of fill (distilled spirits bottled after December 31, 1979).
(a) Authorized standards of fill. The standards of fill for distilled spirits are the following:
(1) For containers other than cans described in paragraph (a)(2), of this section -
(2) For metal containers which have the general shape and design of a can, which have a closure which is an integral part of the container, and which cannot be readily reclosed after opening -
(b) Tolerances. The following tolerances shall be allowed:
(1) Discrepancies due to errors in measuring which occur in filling conducted in compliance with good commercial practice.
(2) Discrepancies due to differences in the capacity of bottles, resulting solely from unavoidable difficulties in manufacturing such bottles to a uniform capacity: Provided, That no greater tolerance shall be allowed in case of bottles which, because of their design, cannot be made of approximately uniform capacity than is allowed in case of bottles which can be manufactured so as to be of approximately uniform capacity.
(3) Discrepancies in measure due to differences in atmospheric conditions in various places and which unavoidably result from the ordinary and customary exposure of alcoholic beverages in bottles to evaporation. The reasonableness of discrepancies under this paragraph shall be determined on the facts in each case.
(d) Distilled spirits bottled before January 1, 1980. Distilled spirits bottled domestically before January 1, 1980, may be marketed after December 31, 1979, if such distilled spirits were bottled in accordance with § 5.47.