The Ultra model numbers with the F are fluted barrels of which there are three, all with the synthetic Choate Varmint stock, all Ultra Hunters have 22" sporter barrels, except the 444 and 45-70 thumbhole versions which are heavy 24" stainless. Ultra Varmints are all 24" bull barrels, they come with laminated monte carlo or thumbhole stocks. What's marked on the barrels is irrelevant other than the chambering, barrels are made in runs of 50 to 500, what model they end up on is up to them, barrels have been marked with lots of different names over the years, some say Handi-rifle, SB2, SB2 Ultra, etc.
Tim
