Eva:
According to my research related to the long arms used by the 30th Mississippi Infantry during the Civil War, that regiment did have some .58-caliber "Mississippi" rifle muskets. That rifle was a favorite among Confederate soldiers because of its long range accuracy. Although originally issued in .54-caliber, after 1855 many were rerifled to .58-caliber U.S. standard. The Model 1841 Mississippi rifle was the first general issue percussion shoulder arm manufactured in government armories between 1841 and 1855. Known by some as the "Jaeger" rifle, the Mississippi rifle was used extensively by the North and South during the war. The Mississippi rifle received that name after the U.S. Government had issued them to the First Mississippi Regiment during 1847. Confederate forces later captured those rifles and used them against Union troops during the Civil War. The above information is taken from the book, Oh for Dixie! The Civil War Record and Diary of Capt. William V. Davis, 30th Mississippi Infantry, C.S.A., by Joe & LaVon Ashley (pages 14,16, and 17).....Joe Ashley