semiautomatic vs self-loading

semiautomatic is a noun but self-loading is not a noun.

Word	Noun	Adjective	Verb	Adverb
semiautomatic	Yes	Yes	No	No
self-loading	No	Yes	No	No

As adjectives, semiautomatic and self-loading are synonyms defined as:

semiautomatic and self-loading: (of firearms) capable of automatic loading and firing continuously

Other synonyms of semiautomatic include autoloading.

semiautomatic (noun)	self-loading (noun)
a pistol that is a semiautomatic firearm capable of loading and firing continuously

semiautomatic (adjective)	self-loading (adjective)
(of firearms) capable of automatic loading and firing continuously	(of firearms) capable of automatic loading and firing continuously
partially automatic