Help Identify this Officers Visor Please

[Jammanna]

Any one know what branch/rank of service I have here?
It was accompanied by two WW1 Us helmets if that's of any help

[GlennAgain]

Regular Army, Artillery.

[Jammanna]

Thanks I see them now, however i do not see any that have the bullion emblem. Do you think this is a WW1 period visor or later ?

[Tim030]

Vietnam to about 1980 I believe. Company visor

[stonemint]

Great cap--can we see a pic of the interior?