Those two citations are interesting, but given the free wheeling nature of 18th century punctuation they may just be lacking commas and not specifically denoting attached bags and horns.
This one certainly nails the attached mode.
Collections of the Georgia Historical Society, Volume 5
2d Georgia Battalion Elbert's Orderly book
Regimental Orders, 2nd Battalion
12th July, 1777.
"...The regiment to parade precisely at four o'clock this afternoon, each man with as much loose powder in his Horns as will make Nine rounds, with black moss [aka Spanish Moss] for wadding;
the Colo. can have no doubt but that every man in the Regiment has a powder Horn slung to his pouch after so many repeated orders for the Purpose, as the Companies are all informed they are in future when every under arms to appear in them..."