.45 caliber vs .45-calibre

.45 caliber and .45-calibre both are adjectives.

Word	Noun	Adjective	Verb	Adverb
.45 caliber	No	Yes	No	No
.45-calibre	No	Yes	No	No

As adjectives, .45 caliber and .45-calibre are synonyms defined as:

.45 caliber and .45-calibre: of or relating to the bore of a gun (or its ammunition) that measures forty-five hundredths of an inch in diameter

Other synonyms of .45 caliber include .45-caliber, .45 calibre.

.45 caliber (adjective)	.45-calibre (adjective)
of or relating to the bore of a gun (or its ammunition) that measures forty-five hundredths of an inch in diameter	of or relating to the bore of a gun (or its ammunition) that measures forty-five hundredths of an inch in diameter