A couple of years ago Phil Price from AirgunWorld magazine gave me one of these that he had in his shooting bag

http://i90.photobucket.com/albums/k2...psa7c3ed79.jpg

The 'ball' end seats the pellet perfectly

I believe that these were once given away free with the magazine

Using the ball end of the tool as a guide I made a 2nd out of wood as mentioned above