Most of the well known, and named weapons in the RBU are melee, so the search for the greatest ranged weapon may take more time. Most of the weapons that fall under this will not be seen in the top 10 melee, unless they are both melee and ranged. If you know a weapon that isn't one here and it exist in the RBU that you think should be one here, contact Kevro.
http://www.ranker.com/list/top-10-ranged-weapons-in-the-red-bungie-universe/kevrorobinson,
Pope Fox's Machine Gun
This gun is seen in the Barren vs Drunken Fellas videos, and soon in the full animation. This is a standard weapon in the Drunken Fellas Army, mostly used by the Grunts and Front Line crew, unfortunately it has little effect on Barren. It will put nice holes in anything that doesn't regenerate though.
Dyna Mike D's Sniper Rifle
Dyna Mike joins in in the first against Barren, he's the point man with a sniper rifle, but in this battle he ends up being unable to do much more then be a medic, by the time Pope and Mike D got to the battle there was collateral damage. The weapon is a standard class piece from the Drunken Fellas Army.
Dark Knightly's Oozies
Who doesn't love two jet black oozies and a baseball bat as their weapon list. Dark's oozies are a powerful Zombie deterant in the Shootout, he keeps plenty of ammo and loves pissin bullets, when he comes through duck or get hewn!
Robin's Sniper Rifle "LJ2"
Robin's Snipe rifle is his main weapon in The Zombie Shootout he is currently filming. It's got great range and in the hand of a marksman which is Robin's specialty, it's a dangerous one hit kill from a distance. He calls it LJ2 or Lil John 2.
Commander Keen's Plasma Gun
One of the lesser known members of the Red Bungie Universe is Commander Keen, who joins the group "Life Sabers" with Luke, Peter Pan and Samus. He brought his trust Plasma gun which has been upgraded a bit to fire larger blast. It vaporizes many a foe and has 500 rounds.
Dick Tracey's Yellow Revolver
"Pete" the pistol is Dick Tracey's choice weapon in battle. It can be seen in the future Barren fight from the "Barren" series. It's an alien revolver that fires lazer that numb and stun opponents. Against Barren, it fares about the same as every other weapon, poorly.
Steaks' Steaks
These are both melee and ranges, steaks throws them like javelins with incredible accuracy. The simplicity and diversity of the weapon is what made steaks choose it. As he's often attacked by multiple oppoents at different speeds he has to be able to quickly read and react in battle.
Energizer Blaster
This is the most diversely used gun in the animations so far. It's been wielded by Jay W, Casey Jones, Mario, Barren (though not fired,) and Gun (the Green clay man,) who was the first to be seen with the weapon in a RBU short called "Gun vs Knife." The weapon takes the users current KI energy level and allows them to fire energy blast at that level. It does slowly drain the energy and tire the user but it's a powerful weapon in the hands of a High KI energy being. It has been fired more times at Barren by more beings than any other weapon so far.
Robin's Bow
Before Robin was shooting zombies on a moon with a sniper rifle, he wielded a bow in the series "Robin of Lego." He's a very accurate marksman, he many times ends up using his sword when combat closes in, but when in range he can pick of a few guards without being detected.
Chris' 50 Cal
Nothing like a nice 50 calibur to set the mood, The Great Schamalama uses the biggest gun in the Drunken Fellas Army and it does it's job well. There's no footage of it in action yet, but in part 2 of Barren vs Drunken Fellas, look for this weapon to come in to play.