Related Rule
Cameroon
Practice Relating to Rule 77. Expanding Bullets
Cameroon’s Instructor’s Manual (1992) states:
These [small calibre] weapons are those which shoot bullets at very high initial speed and which cause excessive trauma comparable to that produced by dum-dum bullets
These bullets, unlike traditional bullets, spread or flatten out after entering the body to create a wound larger than their own diameter, thus causing excessive injury. 
Cameroon, Droit international humanitaire et droit de la guerre, Manuel de l’instructeur en vigueur dans les Forces Armées, Présidence de la République, Ministère de la Défense, Etat-major des Armées, Troisième Division, Edition 1992, p. 125, § 442.1.