Pics of the entire coin would help, but... ... did they even *make* a Carson City mint-marked dollar in 1799? Methinketh not...?
If all the images are of the same coin, it's fake. It's best to post full images of both sides of the coin.
The mint minted coins in 21 different years. The Carson City Mint was created in 1863 but wasn't put into operation until 1870. It ran until 1885, went on a hiatus, and resumed operations in 1889, after which it ran until 1893 when it closed for good. It is now the Nevada State Museum, Carson City. So you can't have a real 1799 CC dollar.