I really really wanted this rifle when I saw it, so I tried farming it for a few days. There is a 4 man quest on Belsavis, if you do it you can choose to get a level 44 jewelry box, this is what you are looking for. The level 44 jewelry box contains an orange level 43 weapons almost everytime you open it (same level as the wraith infiltrator).
Other than that quest, what I did was auction in the fleet to "buy" belsavis commendations for like 10,000 credits per 8. The other person can buy the level 44 jewelry box from the Belsavis vendor, then you can purchase that box from them. Apparently you can also get the level 44 box from the Voss vendor as well.
Happy farming. Soon! http://i.imgur.com/g7Al6.jpg