Your Hunter Classic and Call of the Wild accounts must both be connected through the same Steam account. You can do this by launching the Hunter Classic through Steam.
You then need to run your account details through the Promo Claim site.
Once you have, the .270 Warden Rifle and the Dry Leaves Ghillie Suit will be credited to your account. They won't be in your starting load-out, but will be available when you reach the first outpost and will be available to buy in store as part of the leveling up process for the game.
Once you have been to the first lodge and checked, if they don't show up in your inventory, please contact us with your The Hunter Classic and Call of the Wild user id's and we will look into this for you.