Ted --

Since most members of this regiment were in prison when Congress passed the military law of April 16, 1862, reorganization under the law was delayed until prisoners were paroled and exchanged in late September of 1862.

Unless Pegram was recaptured afterwards, he probably wasn't paroled again until the end of the war. The date should be April 1865 rather than April 1863.

Here's a history of this regiment --

http://www.tngennet.org/civilwar/csainf/csa50.html

I'm assuming you have the soldier's service file. Let me know if you have other questions.