Heavy Weapons

Because of their incredible strength, Champion can carry into battle weapons far too large for others to lift. Gatling guns, plasma cannons (if your Squad has access to advance tech), mortar round launchers and enlarged shoulder-mounted rocket launchers are all possible. 
Explaining how your Champion acquired the weapon might be difficult depending on the Genre and setting of your story, but if you have a Creator or King Adept in your Squad then maybe they made it / bought it for the one guy in the group they knew could use it.