The previous post is correct that the federal firearms laws (Title 18, United States Code, Section 922) prohibit a former felon from possessing a firearm, regardless of the type of crime or the age of the conviction. First, was your prior conviction as an adult? Juvenile convictions generally don't count. Even if your prior conviction was as an adult, you have two routes available. First, you could file a civil suit seeking to overturn the federal statue as unconstitutional as it applies to you. There has been a lot of recent court decisions regarding the Second Amendment and there has been some suggestions in some cases that the broad prohibition against possession of a firearm is unconstitutional when applied to ex-felons whose prior crime was non-violent and who do not otherwise pose a risk of violence. Second, the federal statute only applies if your civil rights have not been restored. You could consult an attorney in your area who is knowledgeable about Ohio's laws in particular to see if you can have your civil rights restored. Good luck to you.
I don't practice in OH.
DC v. Heller specifically excludes felons not being allowed to have guns from 2d Amendment consideration.
Consult a local attorney about a pardon, certificate of rehabilitiation or other similar vehicle that may get your rights back.
Edward J. Blum