The Confederate soldiers involved in your quotation were almost certainly equipped with Austrian rifles with Type I sights. Beyond 250 paces, they would have had to have used "Tennessee elevation." The Enfield rifle muskets would have been equipped with the standard long range Enfield sight. The artillery battery was presumably more than 250 paces away. In this tactical situation the advantage would have gone to the Enfield rifle musket purely on the basis of the sights.
Greg Edington is correct ragarding the Lorenz design bullet. When properly fitted to the bore - .001 to .002 inches under bore diameter - and using a powder charge adequate to slug the bullet up to bore diamter, it is an extremely acurate bullet, more so than the Minie. It is also much easier to cast in quantity than the Minie bullet.
Regards,
Don Dixon