WWI US Army Draftee Squad RPPC, Artillery Men Back From the Range?

Description

Selling a few photos for a friend and this squad photo is pretty nice.  It looks like they're wearing artillery discs (though one might be infantry), and one of the men is wearing a USNA or USNG collar disc.   The Sgt at left looks like an old hand, probably their drill instructor.
Some slight bruising to the right side corners, otherwise no major condition issues with the card.