my online dating consultant mike muson - Dating firearms by seral number
Three are proofmarks, and there is a fourth that is a Spanish military acceptance proof.
Although many other countries have military acceptance marks as well, I do not know their design; if anyone does know for sure, please send me a good quality photo or other reference information.
Now you can enter the serial number of your firearm and be directed to the correct schematic for it as well as order parts through our partners Brownells, Inc. Additionally, you can see the approximate date of manufacture as well as being able to view/download an owners manual, choke tube information (where applicable and available) and product literature relevant to your firearm when we have the information available. For the search to work, please enter your serial number in all UPPERCASE letters and numbers with no spaces between the characters.
Be certain to not confuse numeric and alphabetic characters, such as O's for zeros or we will be unable to locate your serial number.
Though the US government has inspection processes for military goods, there is no proof house of any sort for domestic US gun makers.