Superhero Packing Heat

90s Kid: "And one of them has the greatest superpower of all, GUUUUUUNS!"

—Atop the Fourth Wall

For various reasons, Doesn't Like Guns is a common thing with comic book style superheroes and supervillains (whether it's ethics, style, or something else). Even before the comics code was written, it was rare to see heroes with guns. Then some heroes who broke this rule caught on, and soon more and more heroes and villains began using guns. This soon became closely associated with the Nineties Anti-Hero, and therefore also fell out of favor when that trope did.

This doesn't have to be just projectile firearms. Lasers will do as long as they are used more like firearms than Ray Guns. Heck, even flamethrowers and bazookas can count. Bonus points if the character is also wearing a Badass Bandolier.

Note: To count, a character has to meet two requirements:

The character has to be a comic book-style superhero or supervillain.
The guns have to be one of the prominent "powers" of the character, not one of the character's lesser-used weapons.

Compare The Gunslinger, Girls with Guns, Heroes Prefer Swords.

Examples of Superhero Packing Heat include:

The earliest comics featuring Batman had him using guns. This got retconned moderately quickly once writers realized that having Batman kill all of his adversaries in one issue meant that he'd have no one to fight later and they'd have to rack their brains thinking up new ones too often. Once he started hanging around with Robin and it was revealed his parents had been killed by a gunman, it went away entirely.
- In modern continuities, this gets a Call Back every so often, usually under the guise of a "Year One" story or a alternate universe. The main timeline Batman has used a gun against another sentient being with aggressive intent only once: in Final Crisis, after Darkseid has become such a threat that everything is on the table. And even that might have been retconned with the recent semi-reboot of the DCU.
The Punisher. This is what tends to make him stand out among the pack, as a gun-toting vigilante who fights like a soldier contrasted with a world of spandex-clad weirdos.
- Not so much in the MAX series, which lacks superheroes.
Cable of X-Force. His guns in particular can go Serial Escalation in size and improbability of design. How about one barrel the size of his head, and several smaller barrels beneath? (This from Phalanx Covenant.)
Bishop of the X-Men, as a cop from future not unlike that of Judge Dredd, used guns when he first arrived, and an ongoing Character Development plotline for him was learning to tone it down and not use lethal force. He also had the power to shoot energy rays, but used guns frequently as his power depended on external sources of energy to redirect.
- One version of his guns actually channeled his own powers.
90s Kid of Atop the Fourth Wall parodies this, saying the coolest superhero ever would be named "Bloodgun", and he'd be a man made out of guns, even his head.
All versions of DC Comics' The Vigilante, except the original singing cowboy from Seven Soldiers.
- Actually the singing cowboy version did pack a pair of six shooters, but was very much a fan of Blasting It Out of Their Hands.
Also from DC Comics is Wild Dog, who looks like he should be a parody of the trope, but sadly isn't.
- Max Allan Collins noted in Amazing Heroes #119 that he created Wild Dog as a sort of modern update of Zorro, The Green Hornet, and The Shadow, who all predated Superman and Zatara, and Collins carefully distinguished between a costumed hero and a metahuman hero. Collins did not intend Wild Dog as "super".
Ballistic, one of the "New Bloods" from DC's Bloodlines event.
Several of the characters in Watchmen, notably The Comedian.
Big Shot from The Tick (animation) is a parody of this. He would lug around BFGs and unload into harmless inanimate objects while crying about his mother.

The Tick: Guns and superheroes don't mix. Seek professional help.

Hitman. His powers are telepathy, X-ray vision, and lots of guns — not necessarily in that order.
The members of the gang "The Disco Boys", who use a Disco theme, in Mystery Men get ragged on by the heroes for their superpower being guns:

[commenting on The Disco Boy's arsenal]
Mr. Furious: What? Guns? That's your power, you shoot guns?
The Blue Raja: There's no theme at all here.
Mr. Furious: Weak.
The Blue Raja: At best.

The Phantom: While he tries to avoid actually killing people, he's very much willing and able to if necessary. Previous incarnations gladly used swords in the same capacity.
City of Heroes has the Dual Pistols and Assault Rifle powersets for ranged archetypes (blaster, corruptor, defender). Also, Thugs masterminds lead a group of gun-wielding henchmen and have their own pistol attacks.
- The Masterminds also have the Mercenary powerset, which works like Thugs, but with assault rifles.
- Robotics Masterminds get a Pulse Rifle which straddles the line between this trope and Frickin' Laser Beams
- And now they have just introduced the Beam Rifle powerset.
Why Badass Normal Jessica is so Badass.
Captain America's original incarnation had him using guns in addition to his famous shield, since he was a Super Soldier fighting the Nazis during World War II. His movie also aims in this direction (justified, since it's During the War). As you can well imagine, fan reactions are...somewhat mixed.
- Bucky also used a gun when he took up the identity of Cap.
- Steve has started packing heat again as Commander Steve Rogers, Head of S.H.I.E.L.D.
In the Global Guardians PBEM Universe, Sniper is a Punisher-style vigilante who uses gym-bags full of guns. He thinks of himself as a hero; most of the heroes see him as a villain.
During a period where he lost/repressed his primary powers (eye-beams), Cyclops of the X-Men carried a pair of pistols for offensive purposes in the field. It complimented his secondary power of innately understanding angles and trajectories, letting him pull off incredibly accurate and tricky shots.
Marvel's Deathlok (aka Michael Collins) has a plasma gun, plasma rifle, and plasma grenade launcher. This is in addition to his intelligence, hacking skills, and other super powers. His main challenge is usually to overcome his adversaries while preserving his Thou Shalt Not Kill ideology.
Big Daddy and Hit Girl from Kick-Ass. Of course in the comic Big Daddy is not technically a superhero - just a psycho with lots of guns.
While most Power Rangers teams have sidearms of some kind, it's the more officially-sanctioned ones that make extensive use of them, like the Space Police SPD and Time Police Time Force. The Lightspeed Rescue team in particular has a reputation for favoring their blasters.
Champions Online contains the Munitions powerset. This includes everything from dual pistols as the lowest level attack (and several higher level ones), through submachineguns, shotguns, assault rifles, a minigun, a rocket launcher, and more.
The Scarlet Spectre of Freedom City's Time of Vengeance campaign, is a B-Level vigilante who, lacking superpowers or much money, fought crime with her father's .45 pistol.
This is of the most obvious ways The Twelve, a random group of Fish Out of Temporal Water from the last days of World War II, illustrate the Values Dissonance between their time and ours. A full half of them carry guns, from the Badass Normals like Mr. E, the Witness, the Laughing Mask, and the Phantom Reporter, to Flying Brick Captain Wonder and powerful psychic Mastermind Excello.
The Crimson Avenger in The DCU. Both the original in his Coat, Hat, Mask phase and the Nineties Anti-Hero successor. The legacy character takes this further, claiming that the original CA's chest emblem during his superhero days wasn't a sun - it was a bullet hole.
The DC Comics Elseworlds story Superman: At Earth's End had a mostly-depowered Superman take up a ludicrously oversized gun in order to fight twin clones of Hitler. Then it went on to include an anti-guns message at the end.
Akemi Homura from Puella Magi Madoka Magica is a Magical Girl Packing Heat. No, that arsenal she carries doesn't come from her Magical Girl powers: she stole it from the Yakuza and the military.
- Mami also who uses Flintlock rifles, but these are magical.
Death The Kid from Soul Eater has Liz and Patty, who transform into guns.
Captain Smiley in Comic Jumper uses his Guns Akimbo as his primary method of attack.
Tombstone from Freedom Force has a pair of magical guns as his primary weapons. They fire bolts of electricity to symbolize his death by electrocution in the electric chair.
Grifter of the Wild CATS and Wildstorm Universe, although sometimes possessing psychic powers, usually favoured Guns Akimbo, switching between his VADs and a variety of mundane pistols.
In season one of Who Wants to Be a Superhero?, the Iron Enforcer's gimmick was a incredibly huge cannon mounted on his arm. Subverted in that Stan the man was never really all that excited over superheroes with guns, let alone huge ones like that, and between his gruff attitude and less than stellar challenge performances he ended up getting the boot. Then on the way out (portrayed as him literally walking out a back alley, when a nearby TV suddenly comes to life) Stan said that he finally figured it out: Iron Enforcer made a lousy hero, but DARK Enforcer made a great villain!
Moon Knight has on ocasion used weapons. But then again, he is a former mercenary and soldier (And in the Ultimate Universe, a former Navy Seal), and is known to be a dark subversion of Thou Shall Not Kill, so its not exactly out of place. Its also one of the characteristics that seperate him from that other Knight.
Savage Dragon has superhuman aim that allows him to shoot without killing, although he has done so when pressed.
Eldritch of the Whateley Universe. The fact that she is Nigh Invulnerable and has magical abilities doesn't stop her from packing heat. In the Team Tactics course at Super-Hero School Whateley Academy, she shows up carrying an M16 with an M203 grenade launcher slung underneath. The course is taught by a Gunnery Sergeant and a retired admiral with Spec Ops experience: neither of them are surprised.
- In fact, Bladedancer asks Eldritch for gun training. No one expects the Chinese martial arts nut with the magic sword to also be packing an automatic.
The Shadow is either a superhero or a proto-superhero depending on who you ask, but he wields a pair of automatics.
Orson Randall, the former Immortal Iron Fist, uses a pair of handguns, for which Danny Rand, the incumbent, gives him grief. "So you learned your kung-fu from Lei Kung and Smith & Wesson?"
One of Iron Man armors, the Variable Threat Response Battle Suit (A.K.A. War Machine), used a minigun and a chain gun as main weapons. Jim Rhodes will be the main user of this armor, with successive iterations including increasingly heavy gun-based firepower.
- This carries over into the movies: during the final fight when they're being attacked by drones in Power Armour, Iron Man punches them or uses his repulsors while War Machine just unloads with the cannons.
Shadehawk, the protagonist of Antihero for Hire.
Son Of A Gun ("Superhero #1") by KMFDM. Iit's hard to tell what he uses, but it involves massive explosions.
Spawn seems able to pull any sort of weapon, ancient or modern, from the Hammerspace of his cloak, and has pulled guns from it from time to time.