High poly model of a shotgun tutorial found here http://www.polycount.com/forum/showthread.php?t=100984 I shall continue to post as I do more, had a few issues using Maya for some of the things shown in the tutorial as it is done in 3DSMax but it was easy enough to translate the skills to Maya Comments and criticism…
The stock and receiver should align and not have as noticeable a bump, see ref Otherwise the model looks fairly well done, although the render is too small to pick on small details. You should continue on to the bake and texturing stages.