Help dating crossed cannons hatpin

[olas13]

Thanks for looking. I have this hatpin and was curious to an age or time period?
It's been in the ocean a long time.
thanks in advance. HH.

 

[TheCannonballGuy]

There are two time-dating clues for your US Artillery crossed-cannons insignia:
1- The shape of the cannons, having "narrow" barrels with a round trunnion instead a handle, is the version first issued in 1905.
2- Having a "screw-pin & disc" on the back for attachment to the uniform began about 1895 and ended in the late-1930s.

My guess is you found the 1905-to-1917 version of US artilleryman's hat-insignia. You can see a photo of that version at the following webpage. You can narrow down the date-range a bit further by carefully measuring your insignia and seeing if it matches up with a collar-insignia or a hat-insignia, here:
Evolution of U.S. Army Artillery Insignia

Also, the numbers 0 and 9 (in that order) on your insignia suggest either the 109th or 209th or 309th Artillery Regiment. If you're interested enough, do some research to find out when those units were first formed.

 

[olas13]

Many thanks Cannonball! I'll do some more research. HH.