I've checked my roster information and the only Raines in the 2nd Mississipppi I have that might have gone by "Bert" is James A. (as noted in a previous post by Ron Skellie, the "A" could stand for Albert). You can find a summary of his service at the link below:
He was named to the Confederate Roll of Honor for his actions at Gettysburg on July 1st, 1863 where he was severely wounded and captured (right foot was amputated).
Hope this helps...