I just purchased an A-5 at a local auction and Im getting different opinions on the manufacture date. The serial# is 46450 with an M above the numbers. One person tells me that it was made in 1914 and another said 1928 and I just called Brownings historical dept and he says it is 1954 and the M is for standard weight but on Brownings web site it doesnt have the M listed until 1957.
If anyone else has an opinion I be happy to hear it.

Your is the standard weight 12 and was made in the first half of 1957.

To firm up the date....M 35250 was made on 12/31/56 and M 59550 was made 6/30/57.

Browning provides horrid information on Auto-5's

Jeff