Lest they were confused with other characters, I and Q were not utilised, so the date letters to 1941 were as follows 1922/23 - B; 1923/24 - C; 1924/25 - D; 1925/26 - E; 1926/27 - F; 1927/28 - G; 1928/29 - H; 1929/30 - J; 1930/31 - K; 1931/32 - L; 1932/33 - M; 1933/34 - N; 1934/35 - O; 1935/36 - P; 1936/37 - R; 1937/38 - S; 1938/39 - T; 1939/40 - U; 1940/41 - V.The alphabet was restarted several years post-war in 1950 with A, but now each letter change was made at the beginning of the year.
However, we have been made aware, by a contributor, of two contemporary rifles, a BSA Mk.II Lightweight Martini International and a BSA Century, that each carry what certainly appears to be the letter "I" in the left quadrant (as in Fig. This would suggest that "I" as well as "Q" was no longer deemed to be ambiguous, as had previously been the case with the Fig.1 stamp configuration."The Broad Arrow", and "The Lee-Enfield Story by Ian Skennerton, afford many specifics of manufacturers' and unit codes and proof marks, and of rifles of Enfield origin respectively. Akin to the longstanding hallmarking system for British silverware, in which letter codes relate to years of manufacture or importation, is an equivalent employed by the British Proof Houses.The problem here is that, unlike silver hallmarking, the Proof House codes were only introduced in 1921 and have been only intermittently applied since then, almost on the whim of the Proof Master incumbent at any particular time. production was proved at Birmingham and the marks should therefore comply with these series.It is to be found under the barrel just foreward of the receiver, and requires removal of the fore-end woodwork to view. It is possibly the diminutive size of this mark, and its usually hidden location, which has led to it being described as 'secret'.
In this instance, the code letter is 'M' for 1932-33, indicating that the rifle was manufacture, or at least proved, between July 1932 and June 1933. Post-War rifles such as the BSA Model 12/15 will not carry this mark.The system ceased to be used during 1941, since there was practically no civilian firearm production for the next five or six years, and, with war-time production levels reaching unprecedented proportions, almost all military proofing was effected within the various manufacturing facilities by Government inspectors. However, such date codes as there are are still useful in dating the many firearms manufactured between the First and Second World Wars, including much output from the Birmingham Small Arms Company ( see also BSA Rifles), as indeed is true post 1952 for those rifles more recently falling into the classic class. These marks are also not to be confused with the crossed flags stamp of the miltary proof markings, which may carry similar letter codes identifying the country and/or place of inspection.This so-called "secret" marking system was as follows, with the marks illustrated below applying as indicated. From 1921 to 1951 Figure 1 applies, and for firearms proved between mid 1921 and mid 1922 the code letter is A.For BSA and Greener rifles view complete catalogues from 1908 to the mid 1930s on our CATALOGUES PAGE As far as civilian rifles are concerned, some manufacturers have their own dating systems, with, for example, prefixes or suffixes to serial numbers providing that information.Anschutz target rifles fall into this category, and their system is given on the page for these rifles. manufacturing’s need to machine geometry based on mean dimensions and tolerances.