Navy Button?

[freemindstuck]

Hi,
I've been hunting an estate built in the late 1870's. Tonight I popped a shallow bottle cap and rescanned and got a jumpy signal which turned out to be this button. It was at about 5 1/2 inches. I'm hoping someone here could help me date it? I'll post more relics and coins as I get them cataloged and photographed.
Thanks for looking.

 

[HEAVYMETALNUT]

with no backmark & that type of shank i'd say 1940-50 ish civilian blazer button

 

[del]

i'd agree with Dave , maybe a bit older