I found a report of the Armerment of Fort McDermont, which was manned by Owen's Battery, 22nd Louisiana and Massenburg's Georgia Light Artillery. The list includes "a Brooke Rifle, six smothbore rifles, two twenty-four pound howitzers and six mortars."

Of course there is no "smoothbore rifle" but it makes me thank that most of the field guns were the ones that Ownes signed for at Selma in June 1864.

Williamson, David "The 47th Indiana Volunteer Infantry: A Civil War History", (McFarland, 2012), Accessed 27 December 2012, http://books.google.com/books?id=ZprTBc5shLwC&pg=PA270&lpg=PA270&dq=%22owens+arkansas+battery%22&source=bl&ots=70MPkJQj8O&sig=w5oNRGym_bolU19WOyXKOJkIGrM&hl=en&sa=X&ei=og3dUIfILuLg2AXm5oCYDA&ved=0CFIQ6AEwBjgK#v=onepage&q=%22owens%20arkansas%20battery%22&f=false