flat point nose punch?
get a bolt that will fit and cut the head off and use it.
otherwise you can get a top punch, hot glue gun and some syran wrap.
get the bullet you want, cover it with syran wrap, put the "unfitted" top punch in the sizer and then put a big gob of hot glue from the glue gun on the top punch and the top of the bullet, lower top punch onto bullet, let it cool.
after cool, take out and trim as needed. tadaaa, custom top punch.
