If the reaction is with diluted aqueous ammonia (formely NH4OH) then the product will be the hydrolysis one - ammonium salt of the butiric acid. If you are using concentarated solution of ammonia then the product should be a mixture of the ammonium salt butiric acid, the opened ring gamma-hydroxy butyroamide and may be some of the ciclic butirolactame. If using pure ammonia NH3 the process will be in fact aminolysis and the product will be predominantely the cyclic lactame especially if using and some hygroscopic agent as anh. Na2SO4.