If we are talking about a browning auto-5 shotgun,and the serial number is 1M not IM then your shotgun was a standard weight model auto-5 shotgun in 12 Gauge that was made by FN of belguim for browning in 1961.
Your belguim made browning auto-5 standard weight shotgun was made in 1962.
The H prefix to your serial number indicates that your browning standard weight auto-5 shotgun was made by FN of belguim for browning in 1954.
Your Browning standard weight model auto-5 shotgun was made in the year 1954 with the serial number that you have provided.
The Browning website has a page enabling you to find your shotgun's age, but you have to know the type of shotgun you own. Go to the page, then click on the type of shotgun it is - there are 15 types - and then reading the page for that gun's serial numbers. Look for the series of serial numbers that includes the one you are interested in: #48162.
Your serial number indicates that you have a standard weight Browning auto-5 shotgun that was made in the year 1958.
Your serial number indicates that your Browning standard weight auto-5 shotgun was made in the year 1952.
Your serial number indicates that you have a Browning auto-5 standard shotgun in 16 gauge,that was made in the year 1953.
With the serial number that you provided,you have a browning auto-5 standard weight shotgun that was made by FN of belguim for browning in 1955.
47571.With the prefix of 1M to your serial number;this indicates that you have a Browning standard weight auto-5 shotgun which was made in the year 1961.
Your serial number prefix of 0R which is read zero R indicates that you have a Browning auto-5 standard model 16 gauge shotgun,which was made in the year 1960.
Your serial number indicates that your Browning auto-5 16 gauge shotgun was made in the year 1948.