The period 1876-1880 is far less complicated than the previous period but still has a few complications which need to be covered. In the year 1876 a new obverse started to appear although the reverse die was not changed and continued in use until 1880. Coins using the new narrow ribbon obverse die where minted along with coins that used the previous wide ribbon obverse die for the years 1876 and 1877. This new obverse die continued until 1880, when a new obverse die of 136 denticles bearing the fifth head started to be used.. The half sovereign is the only denomination on which die numbers can be found on coins bearing the date 1880. The various types of half sovereigns that were minted in 1880 will be explained later.
A Study into Die Numbers Found on British Half Sovereigns in the Period 1863 – 1880, Part 3 1876 – 1880 – Brian Unsworth LLB
BNS Research Blog 
The author of this article is unaware of recent research published at the end of last year in the British Numismatic Journal 2024. The article “Victorian Die Numbers: Their Purpose and Their Demise” by Howard Hodgson (pages 189-211) gives a comprehensive explanation as to why die numbers were introduced in 1863 and why they ended in 1880. Hodgson’s article also undertakes a review of numismatic literature published over the last 150 years, pointing out that many inaccurate accounts have been offered as to the reasons why die numbers began but, equally, that several correct versions have also been written. Brian Unsworth’s article on die numbers and half-sovereigns has been written without reference to any of the previous research on die numbers and offers speculative and inaccurate explanations. It should be revised to take account of the most recent research.