But Viking is cheaper.

That's why its an xt item. However, if you have watched the vlogs, you should know that they are working on m2 railgun xt instead of the m3 available by the missions.

If 118ish is ur max, then the railgun usually will do the average damage, in between the highest and lowest points of its damage range. It won't be dealing 118 damage all the time. If it isn't the max damage, then first of all good job, and second of all kostas604 has answered this.