Here's his findagrave entry -
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=McIntosh&GSiman=1&GScid=2305285&GRid=55193305&

McIntosh's service record is practically identical to that of McDaniel Reaves. One difference -- he enlisted a few days earlier, Feb 2, 1863. We can guess that the company advertised for recruits while posted at Choctaw Bluff and these two responded to the ad.