Was talking to a friend about BP hunting with traditional rifles and he gave a tip that I'm wondering about. After loading the rifle before going out, he removes the nipple and adds a couple grains of powder under the nipple. He says that it gives more combustion from the cap and reduces the possibility of a misfire. This brings a couple questions...1) Is this safe or is he about to launch his nipple behind him and 2) if this is safe, what type of powder would you recommend? I'm thinking that pistol or flintlock powder would work better than the rifle powder used in the main charge. Any ideas?