I bought a Browning 16 ga in the mid 1950's. It is probably an Auto-5 and I believe the Serial No. is R 18544. I found one reference that says in November, 1953, Browning changed their model codes to "S" for sweet sixteen and "R" for a standard 16. Neither the Browning site nor another other site with Browning Serial Nos. that I have found shows an "R" and the numbers do not fit either. Made in Belgium is stamped on the barrel so I assume it is not a Browning manufactured by Remington. I would appreciate any information.