One Penny 1927 & 1930 [solved]

I'm new on here but I have a 1927 penny and a 1930 penny. Why is the head on the 1927 bigger than the 1930 penny ? Also the words. Do I have something rare ? My camera sucks - I can take another picture of it later if anyone would like me to to help me out with this. Thxs

Welcome to Numista!
1927:
https://en.numista.com/catalogue/pieces7242.html
https://www.ngccoin.com/price-guide/world/great-britain-penny-km-826-1926-1927-cuid-1130079-duid-1325078

1930:
https://en.numista.com/catalogue/pieces5985.html
https://www.ngccoin.com/price-guide/world/great-britain-penny-km-838-1928-1936-cuid-1129215-duid-1325138

Welcome to Numista (again)!

Petrus said it all; the 1926-27 bust of George V is a "modified" transitional type; from 1928 onwards a small head was used compared to the large ones used before.