As I posted, I'd use a 50% fill of BB's - the video shows 100% fill.
You want the many hammer blows when you smack something.
Martin

On 2/17/2014 10:34 PM, wrote:
I made a mallet (deadblow?) from walnut, maple and BBs. Incredibly fun project.

The plans were taken from Shopnotes 1992 No2.

http://www.youtube.com/watch?v=t-j3UcfQ_rE