They are not that rare. They pop up on the auction sites quite a bit.
This one sold:
http://www.gunbroker.com/Auction/ViewItem.asp?Item=73093357This one did not:
http://www.gunbroker.com/Auction/ViewItem.asp?Item=75518481I would think the home "checkering" job kept that last one from selling.
It was an interesting choice of cartridges. They knew full well that the 44-40 was available both as a regular rifle / pistol load as well as a shot load. So in effect, you were getting a gun that could serve multiple purposes with the 3rd barrel.
Pete
