It's a big bore lever action rifle with a box clip, and probably what makes it look so strange is the absence of a visible hammer. Made for hunting big game in the Northwest, comes in 6 calibers. The big promotion on this rifle was "A classic lever action should handle today's big game loads" I'm not sure the word classic should have been used. The whole idea behind the magazine was so that the Model 99 could use modern bullets. As everyone knows, before Hornady's Lever Revolution ammo came out, a classic tube load could not take any bullets with pointed heads.
These are slowly becoming more collectible, the price has increased by about 300% on a like new Savage Model 99. You can find Savage Model 99's for sale on Gunbroker.com