Citing William A Albaugh III (1908-1983) as an authority, Leech & Rigdon did not produce 1,500 revolvers at Columbus MS.
http://broadfootpublishing.com/singles/The_Original_Confederate_Colt.htm
http://www.amazon.com/Confederate-William-Albaugh-Collection-Series/dp/1568372647
http://www.paperbackswap.com/Confederate-Handguns-William-William-A-III-Albaugh/book/1568372612/

Leech & Rigdon contracted with the Confederate government to deliver 1,500 revolvers. Albaugh notes that Leech & Rigdon made about 350 revolvers at Columbus MS; the company delivered the remainder after Leech & Rigdon moved to Georgia.

Here is #346, which evidently belonged to a trooper of 28th Mississippi Regt.
http://collectorebooks.com/jamesauction/confederate/31350.htm

Once their contract was complete, Leech & Rigdon dissolved their partnership. The subsequent partnership of Rigdon & Ansley produced fewer than 1,000 revolvers at Augusta GA, the highest serial numbers known for Rigdon-made firearms being in the 2300s.

Repeating my earlier question --
Leech & Rigdon produced about 50 revolvers per month at Columbus MS, some being issued to the 28th Mississippi Regt. During September 1862 prisoners from three dozen Confederate regiments were released on exchange at Vicksburg MS. All needed to be rearmed, and Leech & Rigdon production for three months could not have been more than 150 firearms. Among so many other candidates, please explain why officers of the 26th Mississippi would be picked to receive the new Leech & Rigdon revolvers.