Here is a thought. The Coffee County pension application for James J. (J.J.) Stone clearly shows his then current place of residence as "Ambrose, ga," birth place as Irwin County and birth date as 1828. However, on the signature space at the bottom of the application form he made his "mark" in place of his signature when he filed for his Confederate pension in 1904. Obviously, someone else filled out the application for him. Maybe they mistakenly put 1828 instead of 1838 for his birth date. Irwin County was established in 1818, and Coffee in 1854. The two counties were almost next to one another at the time of the War. Not sure if they are currently still the same configuration.
Here is another interesting tidbit to further confuse the issue. Stone's pension application showed that he enlisted in 1862 at Douglas (Coffee County) in "Ashley's Company." However, there was no "Ashley" commanding Company C in 1862. It was commanded by John M. Spence. Although there was a James J. Stone in Company C, 50th Ga Vol Inf Regt, could it be that your James Stone was NOT in the 50th Georgia?
I have spent quite a bit of time researching the 50th Ga roster, and my records show only the following Stones
1. Stone, George R., Pvt. Co A - K at Fox's Gap 9/14/62
2. Stone, James J., Pvt Co C - The one we are discussing;
3. Stone, John W., Pvt Co G - C at Ft. Sanders 11/29/63. Signed oath of allegiance to U.S. Government and joined U.S. Navy 1/6/64;
4. Stone, William, Pvt Co C - W at Chancellorsville 5/3/63 and Cold Harbor 6/3/64. Filed for CSP in Colquitt County 1905;
5. Stone, William H., Pvt Co A - W/C at Fox's Gap 9/14/62, W/C at Gettysburg, C at Cedar Creek 10/19/64 and R from Pt. Lookout 6/19/65. He filed for a CSP in Baker County, Fl 1907.
It is a mystery. I'm not sure what the answer is for now.