Once again, it doesn't matter who is president. Obama has no interest so even if he wins another 4, nothing will change. If a republican wins, he's probably also not going to have an interest. Guns are like abortion, there is no middle ground. People love them or hate them so no matter what you do, you alienate half the voters. It's best not to do anything and hope the issue stays under the radar...
Perhaps you really should have just asked: What is each republican candidates stance on guns and gun rights?