It is a little more then that and there are some differences in brass :(
Did you practice on just two sticks first ?? Popsicle sticks work great, are you not using a washer ???
Some Hardware Store brass rods can be quite hard and need to be Annealed first to get a good peen but this is something that practicing helps you learn.. what size hole did you drill???
Do you have a bench vice to be able to set the peen on one side first or a Jeweler's Block that has been drilled???
I know tons of questions but I am trying to get you to really think about what you are doing, before you rush to finsh, and crack your scales