The gun should go together cocked or not .If itdosent then dont force it till it has been put right as more damage will occur .Try taking the cockin peice ou of the forend being careful not to loose the spring and see if it is that thats the problem . If you can not do this youself go to someone who can. If the guns for sale then it should be sorted before it is sold ,if it is not then ask yourself why and avoid .