Ingredients

We went to the Cavendish Laboratory to discover how fat you would have to be to stop a bullet. We used a gas gun, which is basically a huge air rifle. There is a chamber that is filled with high pressure helium (this is used because it is lighter than air so will expand more quickly).

The gun has a 3m long barrel which you load a small ball bearing into. There is a valve between the chamber and the barrel which can be opened very quickly. The gas (at about 70 atmospheres) then expands extremely rapidly forcing the bullet out of the barrel at supersonic speeds.

The gas chamber which is filled by high pressure helium The bullet - a small steel ball bearing.

A perspex tube was filled with gelatin, which is a similar density to fat, to act as the target.