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

Nice looking mallet!

BUT with no internal loose mass, your answer about " deadblow?", would be
no, not until the bb's slowly deform the cylinders and have more room to
move to give the secondary amount of force to help counteract bounce back.
The more movement the more counteraction to bounce back you will have.

Having said that, walnut being significantly softer than maple might itself
cushion/absorb some of the impact and lessen the bounce back if you don't
strike squarely or until the walnut rounds off or splits off.

If you are building these for a conversation piece, the walnut looks very
nice. For actual use I would recommend that the striking faces be of equal
hardness. As the softer material mixed with a harder material wears away
faster the striking surface naturally becomes smaller and the force is
concentrated in a smaller area. This might leave an unwanted impression on
a wood surface if you are using the mallet for adjustments. That particular
use is what deadblows excel at.

If you used a heavier material, walnut is pretty lite weight, with less
loose mass internally you benefit more with more counteraction to bounce
back.

Now let me throw you a curve on your "force calculation". First off your
equation does seem logical.
BUT an impact driver delivers more efficient force than does a
drill/driver with the same available power supply. It's the multiple
impacts of the impact driver that wins the contest of loosening the stuck
screw vs. the constant force of the drill/ driver..
So while loose shot in a dead blow hammer might seem to have less force at
initial impact the amount of work being done is probably close to the same
given the second impact force of the loose shot. That is going to be hard
to formulate given some loss from the secondary force counteracting the
bounce back. Maybe if the entire mallet striking surface was walnut the
bounce back would be diminished. Whew! :-). Something to think about.
LOL