WHAT IS THIS STAMP ON MY No4 MK1 T?

[Roger Payne]

BSA only used 'M47C' from mid to late 1943 onwards. From 1941 to early 1943 they stamped just the letter 'B' along with the date & serial number on the butt socket. For a time immediately after that, for a few months during 1943, they stamped 'M47' without the 'C' (as per this rifle), & then from later in 1943 they used the full 'M47C'.

ATB