The statutes regulating permits and concealed carry is Title 45, Chapter 9, section 101 (45-9-101), and can be found BY CLICKING HERE.
The only thing I can find in there regarding open carry is near the bottom with 45-9-101 (18). It states, Nothing in this section shall be construed to require or allow the registration, documentation or providing of serial numbers with regard to any firearm. Further, nothing in this section shall be construed to allow the open and unconcealed carrying of any deadly weapon as described in Section 97-37-1, Mississippi Code of 1972.
Now, 97-37-1 is in the section dealing with crimes and details out the penalties for carrying a weapon without a permit. However, it only talks about "concealed in whole or in part".