Everyone doing Oryx should know to have a 295+ sniper. It is not hard to get. Do strikes for an hour. Likely you will get more then one. Doesnt need to even be legendary. Mine was just a blue. The biggest mistake people do is stay in the middle when they fight him. You move closer to him the damage does go up. Whatever it is with his size -blam!-s up the range scaling. Even a sniper and scout will not do full damage to him from the mid.