Hi Phil.
If your friends head weighs only an estimated 450 grammes it is unlikely
to make even a Bronze medal.
Below are actual weights of some heads shot by myself years ago in Sweden and England.
Official CIC measurements by the late G. Kenneth Whitehead and Richard Prior are as stated and also figures derived from my Swedish `Qwik Fix Formula`.
Picture of all 4 heads listed and shown on the photgraph from Left to Right.
Sweden, Gold, [610 Grammes] CIC 134.28 , Qwik Fix 139.6 points.
Sweden, Silver, [520 Grammes] CIC 117.88 , Qwik Fix 118.9 points.
England, Silver, [518 Grammes] CIC 117.34 , Qwik Fix 118.44 points.
England, Bronze, [460 Grammes] CIC 106.3 , Qwik Fix 105.1 points.
HWH.