What you have here is what is called an "automatic center punch" and I have a couple different versions of this style of punch. No offense blue but the punch you have here is made on the other side of the "pond". I don't know/cant tell by your picture if you can adjust the tension on the spring to adjust the hardness of the strike when your punch punches...
Not to gloat.... The punches I have/use, are made by either the General tool co, or Starrett, and have owned punches that look exactly like one that I have owned from Snap On(think snap on has them made for them by general). I also have a smaller (in diameter) style punch that is about the size of a pencil and has the adjustable end on it like Super says, and this punch works well for alot of diffeerent things I do.. I have converted one of the little style to help me remove or plink out dents from the panels that we produce for the automotive industry.