The hammer not striking the nipple squarely can sometimes mean that at some time someone installed a nipple that is either too long or too short. If the hammer is striking the nipple toward the rear of the face of the hammer, it can mean that the nipple is too long. Conversly, if the hammer face is striking toweard the front of the hammer, it can mean that the nipple is too short. To determine how much too long the nipple is, you will need to sacrifice the nipple by carefully and slowly filing it down until it contacts the face of the hammer squarely. Use the lipstick method of seeing where the hammer is striking the nipple. When you have filed it to the point tha tha the hammer is striking it squarely, send that nipple to Track of The Wolf along with an explination of your problem and why the nipple has been filed and have them match the nipple for you. If it is striking toward the front of the face of the hammer, it is too short and you need a longer nipple. This requires that you measure the exact heighth of the nipple to the closest thousandths of an inch. This will require a micromenter. Slowly back out your nipple a quartere of a turn at a time until the hammer is striking it squarely. Again, you will be using the likpstick method to determine when it is striking squarely. Now, measure how much you have raised the nipple, measure the nipple from the base (not including the base or the threads) to the top where the cap goes on. This is how much longer of a nipple you will need. Send this info to TOW along with the nipple that you used to make your measurements including an explanation of what you did and why and they will find a nipple that will work for you.
Or, you can just keep using the nipples that you have and just carefully grind the face of the hammer until it strikes the nipple squarely. Either way will work, it just depends on whether you want to grind your hammer or find a better fitting nipple (if one exists).