Two 5.56x45 cartridges, aluminum case

IMG_1624

I think they came from the United States.
Can someone confirm their origin ?

Thanks
Michel

Produced at Frankford Asenal. Find the info in HWS vol 3.

Here’s a link to Ron Fuch’s 5.56 books
https://drive.google.com/open?id=0B4gsAWd5wuKgUE0tck51U2RMQnc