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3.7 AA primer


Well-Known Member
Premium Member
Could anybody tell me the correct primer number that was used in the 3.7 AA case please.
AA :unsure:
No.9 percussion primer or No.11 percussion primer.

Source. Handbook for the Ordnance, Q.F. 3.7-inch Marks 1,2 and 3. 1945.

The 1939 handbook states only the No. 11 Primer.

The No.11 primer was used with full charge and most of the reduced charge loadings, apart from High Explosive mark 5C & mark 6C foil loadings which used the No. 9 primer. The No.5 primer was used with the Q.F. 2-PR sub-calibre ammuntion and the blank used a No.1 primer.

Hope that helps.

By 1961 the situation was
No. 9
Mark 3/1 upwards for HE Mk 38
Practice projectile Mk 9;
Coloured bursting green, red, orange and yellow. - Mark 4 Cartridges.

No. 11
Primers (all marks). Full charges

The No 17 you were after is an electric primer that appears to be exclusively for the QF 20pdr.

Tim. G.
Here the drawing of the Primer No 9 marks of III Joerg