NSN is a heavy barrel percussion target rifle built by Nelson Lewis of Troy NY.  This example shows a 30" barrel with a fine bright bore 44 caliber.  This maker was in business from 1843 to 1888. 

This is a new built cannon built by a talented machinist.  The tube was turned on a lathe.  The piece is 27 1/2" in overall length, 4" across the muzzle, 5" at the base.  The bore is 1 5/8 and bore

A Blunderbuss originally built as a flintlock and later converted to percussion.  This piece was built by Richardson who was noted for quality and finish of his pieces.  This iron barrel piece show