Complex sentence: H&K and Glock use a female type of polygonal rifling similar to the bore shown above right, this type has a smaller bore area than the male type of polygonal rifling designed and used by Lothar Walther.
Split into simpler sentences: H&K and Glock use a female type of polygonal rifling similar to the bore shown above right. This type has a smaller bore area than the male type of polygonal rifling designed and used by Lothar Walther.