Hello everyone.
Information wonder how to calculate the number of series that can be placed in the tank from the number of the frame bsa m20
Thanks a lot

Which make and model ? In general, with most manufacturers and contracts there is a link between frame number and War Department serial (or 'census') number. This is particularly clear, in the case of BSA, on the later contracts.

In terms of some of the early-war contracts, it can mean pulling together information from a number of sources and arriving at a 'most likely' scenario.

Probably the best thing to do is to post the frame number here and you'll quickly have an answer, with as much detail on how it's arrived at as you'd like.