Well, Mossberg was the big maker of bolt action shotguns. However, as far as I know, all of them were box magazine fed. Various models of the 190 were chambered in 16 gauge.
Are you SURE that the rounds fed through a tube in the butt? That would make the wood in the wrist section of the stock VERY thin, or it would have to be very large to ensure proper strength.
JC Higgins offered a tube-fed (under barrel, though) 16 gauge, the 588.
There's a picture of one here:
http://www.gunsamerica.com/926606925...N_16_GAUGE.htm
H&R also made some, mainly for Sears.
But, once again, I believe that all of them had either box magazines or under barrel tubes; I know of no bolt action 16 gauge that fed via a tube magazine in the buttstock.