[Stig Jarlevik]

Our friend Geoffrey Sinclair wishes to add some thoughts to the subject!

Using published sources, like Fighter Command War Diaries, Battle of Britain Then and Now, the lists of Luftwaffe combat claims etc.

Battle of Britain 10 July to 31 October 1940. Removing all the known non fighter causes of loss like friendly fire, enemy bomber, crashes etc. but retaining unknown cause, enemy action etc.

Overall the RAF fighters claimed around 2,440 kills, for 1,255 actual, or 1.9 to 1, the over claiming by month July to September was around 1.3 to 1, 1.9 to 1, 2.5 to 1, 1.2 to 1, the heavier the fighting the higher the over claims, 15 September makes a big contribution. The RAF was aware of the over claiming given the number of Luftwaffe aircraft wrecks found.

Luftwaffe fighters claimed just under 2,000 kills of Spitfires and Hurricanes, 1.7 Spitfires per Hurricane and shot down around 700, or around 2.8 to 1, a ratio that is consistent July to September, dropping to 2.5 to 1 in October, throwing in the bomber gunner claims explains the reports of the Luftwaffe over claiming 5 to 1.

In 1941 over France the RAF was over claiming around 5 to 1, Ultra told the British about this. The RAF was also making major over claims in North Africa in 1941 and 1942 which can be seen in the Christopher Shores et. al. books.

January to June 1943, RAF fighter command allowed 249 kill claims against Luftwaffe fighters, the true number of kills was 235, according to British Intelligence in World War II (Hinsley).
Looking at 8th Air Force B-17 and B-24 losses the Luftwaffe fighters quite consistently claimed about 2 B-17 for every 1 shot down by fighters, and under 2 to 1 for B-24 ("B-24 easier to shoot down" ideas). The exchange rate of Luftwaffe fighters shot down by the bombers to bombers shot down by the fighters was around 2 fighters to 3 bombers in 1943 becoming 1 fighter per 2 bombers in early 1944.

Theo Boiten in Nachtjagd War Diaries notes only a couple of nightfighter pilots where he suspects their claims.

Making trouble are reports like the USAAF examining a small number of Luftwaffe gun camera films post war finding the most reliable indicator of whether a kill claim was granted was not visible damage, or visible hits, or a fire, but the rank of the pilot making the claim. (91% Major/Captain, 50% Lieutenants, 47% Sergeant). 6 out of 6 claims by Lt Colonels were granted, 1 out of 3 claims by corporals. Total sample size 173 claims.
Stressing these are broad brush figures to give an idea on the size of over claims, not a statement of absolutes.

Cheers
Stig