Here is the review of this piece of equipment.  I found that the Vm to Autococker adapter is a very good addition to the Vm.  This adapter screws in to the mounting area of the Vm and allows most autococker barrels to screw in.  The barrel I have used with this adapter is the J&J strait, rifled, ceramic 14 inch barrel.  There were two things that I found though that a person might want to remember about this adapter.  The first is that the adapter will add 2 inches to any barrel that is put on the Vm.  Second, some chrome autococker barrels will not fit in the adapter due to the chroming process adds a little bit to the width of the barrel and the threads do not match up.  Over all I like this adapter a lot.  It allowed me to add new barrels that I had no access to before and the most important part, unlike other adapters, it did not break balls.  Some adapters don't match up properly with the gun.  I found that the bore of the gun, the rifling of the adapter, and the rifling of the barrel matched completely.