Depends on the gun.
Some guns have the year stamped on them.
Some guns may be identified by the serial number.
Some guns can be dated by particular features they have.
Some guns cannot be dated any more accurately than the nearest decade.
The model number of the gun and make along with the serial number usually will determine the age of a gun.
You are going to have to identify the model number to determine the age. Take the gun to a gun shop or gun smith for assistance.
Try Blue Book of Gun Values
By the features and serial number. Blue Book of Gun Values has sn data.
The age of a gun will depend on what kind of gun it is. If you are unable to identify the gun, take it to a gunsmith or gun collector for an appraisal.
Take it to a Veterinarian. And they can determine the age.
You can purchase .177 pellets at most any sporting goods stores. "Big 5,"' Dicks" or Wallmart just to name a few. As for the age of the Pellet gun you will have to give more information about the "GUN" (It not a rifle?) to determine the age. If you are asking about the model 177 then it was made between 1935-41
The thickness of the shell (lip) increases with the age. This is how you can determine the age of the conch.
The gun was made in 1958
They determine the age by, Radiometric dating of meteorites
Relative age is used to determine the age and how old a geological feature or fossil.
There is no legal age to be able to shoot a gun but the age statue varies from state to state as to what age it can be done unsupervised.