12 an hour is pretty darn good, especially just out of school. you are going to need to work for someone first. School didn't teach you nearly everything and you wouldn't want to open your own shop and ruin your reputation and crash& burn. My gunsmith makes good money but he was in the business for years before opening his own shop 20-25yrs. ago. He also sells guns and has the entire market in a town of 400,000. You also have to be a good businessman, not just a good gunsmith. All the skills in the world won't make up for poor business practices.
"Suppose you were an idiot, and suppose you were a member of Congress, but I repeat myself." Mark Twain