The previous coat of arms reverse design found on the George V & Edward VII shilling series was replaced with a rams head at the start of the new George VI series.
Most coins in the series were minted at the Melbourne Mint (1946 issues were also minted at the Perth Mint). But, from 1942 to 1945 some coins were minted by the United States San Francisco Mint to meet coinage demands of U.S. servicemen based in Australia during Word War II who spent their military pay freely in the Australian markets.
The obverse, designed & engraved by T.H. Paget, features the bust of George the VI facing left. At the bottom of George's neck are the designer’s initials “HP”. On the outer periphery are the words "GEORGIVS VI D.G. BR : OMN : REX F.D. IND : IMP" (latin for "George VI, by Grace of God, King of all the Britons, Defender of the Faith, Emperor of India").
The reverse, designed by W G. E. Kruger-Gray, features the bust of a ram. Behind the rams head to the right are the designer's initials “KG” while on the outer periphery is the denomination “shilling”, country name “AUSTRALIA” and year of issue. Located just below the rams head is the mint mark “S” (San Francisco) while or a dot before the 'S' in 'SHILLING' for the 1946 Perth issue, coins minted in Melbourne did not have a mint mark.
Over the course of the series there were two major changes that created major varieties. The first change occurred in 1946 when silver content was reduced to 0.0908 ounces of silver.
The second variety occurred when India became an independent country in 1947 which caused a change in the obverse legend in 1951 to remove “IND:IMP”.
Variety 1 – 1938-1945 92.5% Silver
Variety 2 – 1946-1948 50% Silver
Variety 3 - 1950-1952 New Legend
General Market Notes
The key to the series is the 1940 issue and the semi-keys are the 1939 and 1946p (Perth) issues.
For a potential undervalued coin look at the 1942 issue with a mintage of only 1,380,000.