Is it possible to make metal fulminates?
In The Preparatory Manual of Explosives  (paperback at amazon), the author, Jared Ledgard, provides a procedure for the preparation of copper fulminate that can be summarized as follows:


  To 100 mL of 70% $\ce{HNO3}$, 30 g of anhydrous $\ce{Cu(NO3)2}$ is added under stirring. If the copper nitrate doesn't dissolve properly, add water dropwise until it does. (NOTE: Adding water to concentrated acids usually isn't the best idea!) The solution is stirred for 24 hrs at room temperature and then heated to roughly 80 °C. Under stirring, 120 g of 95% ethanol are added. After addition of the ethanol, the heat source is removed and the mixture is alllowed to reach room temperature. The precipitate is rapidly filtered off, washed with several hundred mL od cold water and dried in a desiccator over magnesium sulfate. The product, copper fulminate, should be stored in a desiccator over sodium sulfate in a refrigerator.


NOTE 


To my opinion, the procedure leaves out significant information, such as the exact temperature of the aqueous solution while adding the ethanol. It is not clear whether and how much ethanol is supposed to evaporate. While the author suggests to carry out the reaction in a beaker, a setup with a two-neck flask, reflux condenser and a dropping funnel might be a better idea.
Handling fairly concentrated nitric acid requires safety precautions: A fume hood, eye protection, gloves and a lab coat are mandatory!
The reaction product is a primary explosive! While less shock sensitive than mercury fulminate, it still will go off on impact (or upon heating above ~200 °C).


In the case of these or similar sensitive materials, there is a good rule of thumb: If you have to ask on a Q&amp;A site - Don't touch it!