.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