The gun has one fault - the chambers tend to need minor polishing when new else inexpensive steel hulls can stick in them until the gun wears in. I understand this is not a problem with brass base hulls.
The fix is easy and inexpensive. Just polish the chamber for a thirty seconds with steel wool wrapped about a piece of dowel chucked in a drill. http://www.aiptactical.com/Page_2.html
See the part about "new barrels".