WW2 US Navy Captain´s metal eagle insignia vs US Army Colonel metal eagle insignia.

[Flightpath]

Hi,

I´d to know if there any difference between WW2 US Navy Captain and US Army Colonel metal eagle insignia?

[KurtA]

During WW2. A USN captain wore only the small size eagle for the collar. No eagle worn on the shoulder - shoulder boards were worn.  An Army colonel wore the large size eagle for collar or shoulder. 
So the size is the difference.  

[Flightpath]

1 hour ago, KurtA said:

During WW2. A USN captain wore only the small size eagle for the collar. No eagle worn on the shoulder - shoulder boards were worn.  An Army colonel wore the large size eagle for collar or shoulder. 
So the size is the difference.  

Thanks Kurt.👍

[KurtA]

I might add if you’re talking Army vs USMC, it’s much trickier, as the shoulder size would be the same large size.  USMC eagles tend to be a bit more “rounded” (best to look at examples in period USMC photos) and USMC tended to use different manufacturers than Army.  
Bottom line - can be challenging to tell the difference.