Oxidation of Magnesium with Nitric Acid


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> Write an unbalanced equation for the following: Magnesium metal is added to dilute nitric acid.
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My attempt: Nitric acid commonly oxidizes metals and gets itself reduced in the process - to $\ce{NO}$ if the solution is dilute, and to $\ce{NO2}$ if it is concentrated. Therefore, I thought that the reaction would proceed as follows: $\ce{Mg + HNO3 -> Mg^2+ + NO + H2O}.$ 


However, my book says that instead of being reduced to $\ce{NO},$ the nitric acid is actually reduced to ammonium in the following fashion: $\ce{Mg + HNO3 -> Mg^2+ + NH4^+ + H2O}$


Why is the reaction with dilute nitric acid different specifically for Magnesium (as compared to nitric acid reactions with other metals, such as copper) ?


