Can't be answered.
1921
If that is a US Patent, you can look it up on Google, and tell when the patent was issued, but it cannot date the gun- other than we know it would have been made AFTER the patent was issued.
Question can't be answered as posed.
Impossible to date from patent number.
It was selling in Australia in 1964/1965.
No way to tell. You can look up that patent, and it will tell you what year that patent was granted- but there is no way of telling when it was made, other than AFTER that patent was granted.
The Wilkinson razor with patent number 321115 was produced in the year 1931.
Anything that was collected and patent in the year it was made, an issue year can be determined between partners or individual on an exact date and time...
Edward J. Claghorn was the first to patent a seat belt. He has the patent number of #312,085 in year 1885.
With the serial number that you have provided,your Winchester model 1894 rifle was made in the year 1900.
Your original model 1893 Marlin rifle was made in the year 1906,with the serial number that you have provided.
Browning.com has sn data under customer service.