.22 caliber vs .22 calibre

.22 caliber and .22 calibre both are adjectives.

Word	Noun	Adjective	Verb	Adverb
.22 caliber	No	Yes	No	No
.22 calibre	No	Yes	No	No

As adjectives, .22 caliber and .22 calibre are synonyms defined as:

.22 caliber and .22 calibre: of or relating to the bore of a gun (or its ammunition) that measures twenty-two hundredths of an inch in diameter

Other synonyms of .22 caliber include .22-caliber, .22-calibre.

.22 caliber (adjective)	.22 calibre (adjective)
of or relating to the bore of a gun (or its ammunition) that measures twenty-two hundredths of an inch in diameter	of or relating to the bore of a gun (or its ammunition) that measures twenty-two hundredths of an inch in diameter