Chuck, according to DANFS volume 2, page 379, the USS EXCHANGE was armed with two 32-pounders, four 24-pounder howitzers and one 12-pounder. Paul Silverstone's WARSHIPS OF THE CIVIL WAR NAVIES gives basically the same data, with the exclusion of the 12-pounder. No indication is shown of any change in these armaments, so I assume they remained the same throughout the two years of her service in the USN.