Bought this a little while ago, and didn't really like any of the builds. The 2xRAC5 build was alright, but I don't think it's efficient. 2xRAC5 require a standard engine that weighs 30.5t, but 3xRAC2, while weighing 4t more, lets you run a LE and saves you 5.5t. Plus, less spread, 50% more velocity, and 70m more optimal range. They usually don't jam at the same time either so you can basically just hold the button down and pummel someone in to submission. 70 kph isn't the fastest ever, but you have really good range to compensate, and the build runs pretty cold. Takes a long time for the 3xRAC2 to run it in to the red so you have ample time to lay down a serious barrage of screen shake and muzzle flash. If you want more ammo (because I mean, who doesn't want more ammo to throw at heretics?) you can try this build too.