The only Sammons listed in the "Cemeteries of Hart County" publication is Sammons, Benjamin F. in Reed Creek Baptist Cemetery. No dates are given. In the comments section it states "CSA Co B 15 Inf."
There are 35 listings for Osborne - the majority are shown in Reed Creek Baptist Cemetery. There is not a listing for Marietta or O. C. Osborne. There is a C C Osborne (7/17/1879 - 4/16/1948)listed in Reed Creek Baptist - Could be O C that was misread as C C?