I bought a Browning 16 ga shotgun, probably an A-5 from a pawn shop in the middle 1950's and it looked as if it had never been fired. My wife has done lots of hunting with it and I would like to know more about it. There is a number under the receiver which I believe is the Serial No. and it has an "R" with 18544 under it. I have found one reference which says that in November, 1953 Browning changed the model codes and that the R was used for a standard model and an S for the sweet sixteen. But none of the lists of Serial Nos. on the Browning website or any of the other sites I have looked at has an R and the numbers don't fit either. The barrel is stamped that it was made in Belgium. I would appreciate any information.