Gun Accessories



"Gun Salesman: Holster. Bandolier. Silencer. Loudener. Speed-cocker. And this one's *pulls out attachment much larger than the gun itself* for shooting down police helicopters. Homer: Oh, I don't need anything like that. Yet..."

- The Simpsons, Season 9, Episode 5

There are Cool Guns, but when your gun isn't cool enough by itself, what do you do?

Why, you attach a ton of junk to it, of course! What sort of junk can you attach to a gun? Take a gander at the Gun Accessories/Useful Notes page.

As well as all that, you might have non-slip coated surfaces on the weapon to make it easier to handle, as well as camo; most weapons with synthetic furnishings come in a single colour, so additions might be anything from boot polish to actual paint or even bits of foliage. There's also the option of changing the grips for ones more ergonomic than the standard, enlarging or otherwise altering the various levers and controls, changing the trigger and trigger guard, replacing synthetic furnishings with wood or vice versa, or adding tasteless plated finishes and engraving.

Often, more distinctly fictional devices are present, like X-ray scanners, heartbeat monitors, or pointless glowing whatsits. A classic is a visible ammo counter, popularized by Aliens and often used by video games to minimize the HUD. A recent trend in video games is to depict accessory parts as quick-swappable; any potential issues with having to re-zero scopes are glossed over, due to Rule of Cool.

See also IKEA Weaponry, Scaramanga Special, and Swiss Army Gun. Often a Sub-Trope of Gun Porn. For Gun Accessories you're supposed to wear, see Badass Bandolier. Note that with regard to video games, the important thing is that there are physical additions to the weapon; just being able to boost abstract stats to power up weapons isn't this trope, that would be Socketed Equipment. If the accessory itself is another kind of weapon, you may have a Mix-and-Match Weapon on your hands.

Anime/Manga

 * Lampshaded in the first episode of Cat Shit One, where Packy chastises Bota about putting on so much unnecessary attachments on his rifle, remarking that the extra weight will only serve to slow him down. Even Bota half admits that he does it for Rule of Cool purposes, but is later vindicated when his oversized scope helps block a terrorist's sword swing.

Card Games

 * The Good, the Bad & the Munchkin has the Seven-Gun, which is a Six-Gun with a tiny single-shot pistol attached to the barrel. In addition, there's also the enhancers which can change it into My Grandpappy's Steam-Powered Seven-Gun With Unlimited Ammo.
 * The basic Seven-Gun may actually be loosely based on a Real Life weapon, the LeMat revolver.

Film

 * In The Naked Gun 2 1/2, Nordberg pulls back the slide of his pistol and adds an accessory. Then another. Then another. Eventually he's sitting in a full-size antiaircraft gun.
 * Another parody was in Beverly Hills Cop III, which featured an advert for the "Annihilator 2000," a comically over-featured weapon including such extras as a phone, fax machine, CD player and microwave oven.
 * In Terminator, Arnold Schwarzenegger used an AMT Hardballer Longslide equipped with a very early "Laserlock" sight; the prop actually worked, though it ran off a battery pack taped to his back and was triggered using a switch in his other hand.
 * RoboCop's gun was a Beretta 93R fitted with an enormous ported compensator designed to produce a huge horizontal muzzle flash.
 * In Equilibrium, the Clerics use similar weapons; these are converted Beretta 92s with fullauto drop-in sears, M16-style fire selectors and a variety of additional extras, including self-balancing magazines with rounded bases, and magazines with integral blade-things in the base for clubbing people with.
 * The magazine blade-things are reminiscent of a real feature on flintlock pistols in the days of Wooden Ships and Iron Men: Nails in the butt of the pistol that could be used to make it more effective as an improvised club once the one shot had been fired.
 * In The Living Daylights, Dalton uses a Walther WA2000 equipped with a rather large night vision scope and his own hand-loaded ammunition.
 * In the same movie, arms dealer Whitaker shows off a collection of firearms with silly Hollywood embellishments such as mini-missile launchers, and in the final confrontation pulls out a Colt Commando carbine fitted with a transparent gun shield.
 * Eraser featured a scientifically ridiculous railgun with a matching scope; a special X-ray sight that could somehow look through concrete and still see the target's beating heart.
 * Aliens popularized guns with built-in ammo counters; the Pulse Rifles used a very 80s system with simple 7-bar LED displays.
 * Michael Jackson's Moonwalker featured weapons with the same feature issued to soldiers of the overacting drug lord.

Live-Action TV

 * Sledge Hammer's own invention was a special accessory for revolvers. He calls it the "loudener."
 * The Man from U.N.C.L.E. featured a series of custom Walther P38 pistols with various accessories including stocks, barrel extensions and scopes. They proved so popular that the guns received their own fan mail, and Megatron from Transformers was originally a toy version of the UNCLE gun.
 * Watch enough Stargate SG-1, and you'll see all kinds of weapon accessories. The most commonly accessorized gun is the MP5, usually with a scope or ACOG of some sort, or a side-by-side clip holder, but the P90 featured later got in on the act a few times, and light machine guns were rarely stock.
 * Flashpoint shows the police officers using various accessories on their (Weaver Rail) guns, especially tactical flashlights, foregrips, and ACOG scopes. Oddly enough, they almost never actually use the foregrips on their guns.
 * Sons of Guns now features the Docu Drama in tacticool format.

Tabletop Games

 * Shadowrun includes gas vents and shock pads, which provide recoil compensation, gyro stabilization, which offset recoil and movement penalties, sound suppressors, which are silencers for automatic weapons, bipods and tripods, which provide recoil compensation for heavy weapons, and smartgun systems, which tell you when your weapon is pointing at its target among other things. Although the ultimate in gun accessories has to be three choices for a propulsion system or the pilot upgrade.
 * Call of Cthulhu (tabletop game) supplement Terror from the Stars, section "Field Manual of the Theron Marks Society". The title Investigator group would tape flashlights on top of firearms so they could fire at targets in the dark. Eventually they designed custom mounts on the weapons to hold the flashlights.
 * One such weapon is described in GURPS: Gun Fu owned by one "Bubba Lee Jones": Colt M4A1 carbine with twin-drum magazine, a reflex sight, night sight, a tactical light and a targeting laser. He calls her Dita.
 * He even gets bonuses for using Dita since he took the Tacticool perk.
 * Warhammer 40000 rpgs Dark Heresy, Rogue Trader and Deathwatch all have some stuff you can put on a gun. Dark Heresy starts out relatively harmless, with the obligatory silencer, scope and red-dot laserpointer. Rogue Trader and Deathwatch go a little further, supplying anti-grav gadgets that let you use a heavy full-auto rpg launcher while moving and, in the latter case, a chainsaw bayonet. Rogue Trader's expansion Into The Storm finally also featured orks as playable characters, including Mekboyz and a few upgradez and kustom jobz they like to inflict on their guns in their quest for More Dakka. Among them is a loudener which enhances the noise made by guns to ridiculous levels and makes suppressive fire more effective.

Toys

 * NERF N-Strike blasters have Tactical Rails for you to pimp out customize to your heart's content with. Among the numerous Tactical Rail Accessories include a "laser" sight, flip-up iron sights, the NERF version of a grenade launcher, barrel extensions, and for some blasters, interchangeable removable stocks. On top of that, NERF also provides other nifty accessories like the 35 dart drum magazine (for the auto-shotgun Raider), a clamp that allows you to attach two magazines together for a quick-flip reload, and a tripod (for the belt-fed Vulcan). The Recon CS-6 in particular deserves special mention, as it comes with a red-light sight, a detachable stock with space to hold a spare magazine, and a barrel extension with above- and below-barrel tactical rails, an extremely generous helping of tacticool just like a real SOPMOD kit!
 * Many NERF blasters add new toys to the mix: the Spectre revolver comes with a barrel extension made up to resemble a silencer as well as a detachable folding stock, the Alpha Trooper semi-auto shotgun brings with it the 18-dart drum magazine, and the Stampede full-auto assault rifle comes with no less than 3 18-dart (non-drum) magazines, a Tac-rail-mounted ballistic shield, and a foldable detachable bipod stand. On top of that, Tactical Vests and transparent-orange magazines are now available for all you tacticool needs.
 * For even more modgasmic action, the Super Soaker water blasters and the Vortex disc blasters from one toyline have been made with full compatibility with Nerf N-Strike accessories.
 * Megatron's original incarnation was a "The Man from U.N.C.L.E." Walther P38, with an additional barrel extension, scope (which became his fusion cannon) and stock.

Video Games

 * Golden Eye 1997 popularized the idea of a rifle with an adjustable scope.
 * Golden Eye Wii adds an array of Modern Warfare-esque gun add-ons, like underbarrel grenade launchers, reflex sights, ACOG scopes, and more.
 * Perfect Dark had a variety of interesting and odd weapon add-ons, from the relatively normal (the Falcon 2 had a laser module and optional sight or silencer) to the dangerous (the Dragon's internal proximity mine can't be popular with troops when it goes wrong) to the awesome (the Superdragon's underbarrel repeating grenade launcher) to the downright weird (the self-aiming system in the CMP-150). Plus the MagSec 4 pistol was a copy of the modified pistol from Robocop.
 * Parasite Eve 2 had an unusually comprehensive system of Weapon Attachments... some of them was pure boosters, like a bigger magazine for your P08, but other weapons - most noteably the Assault Rifle - had a huge selection of possible attachments. You could mount an underslung Grenade Launcher, sure - but you could also mount an underslung Flamethrower, or an underslung High-Voltage Taser, or an underslung Laser... which was not, I might add, for targeting.
 * Resonance of Fate took weapon-attachments Up to Eleven - Not only can you mount all your weapons with bigger magazines, various scopes and barrel-extensions, but higher-level extensions have, themselves, ports for FURTHER extensions. Towards the end of the game, you'll find yourself wielding an Escher-ish handgun with 8-9 scopes stacked on top of one another, 12 barrels pointing in various directions, 2-3 handles for added stability, and a magazine longer than the gun itself. Assuming you don't go whole-hog with a huge Drum Magazine, but that cuts down on the number of handles and barrels you can attach.
 * Deus Ex's weapon mods, which consisted of silencers, recoil suppressors, range extenders, laser sights...
 * Human Revolution has a number of upgrades and accessories for weapons, including specialty accessories. The generic upgrade packs can boost ammunition capacity, reload speed, rate of fire, and damage. Generic accessories include silencers and laser-targeting systems. True specialty accessories do crazy things to weapons, like the mod to the 10mm pistol that makes it completely ignore armor (one-shot kill on any headshot, even against Ogres), the mod that allows bullets to curve to find the target for the machine pistol and the combat rifle, and the mod that gives bullets a remote detonation system for the revolver. Annoyingly, any accessories that you know the enemy is using (like the laser targeting system on sniper rifles) is either not on the weapon when you pick it up, or incompatible with the weapon when you get it yourself.
 * In BioShock (series), you can find "Power to the People" stations which give one of your guns a single upgrade. Examples include: More damage, larger magazines, faster rate of fire, reduced recoil, better range, no damage from your own shots (for the grenade launcher), random elemental effects (particularly in Bioshock 2) and ricocheting shots.
 * Crysis features a weapon modding system where parts can be swapped onto the various mount points of a weapon; if you feel like it, you can put a sniper scope on your shotgun.
 * Metal Gear Solid 4: Guns of the Patriots features a similar system, with the ability to customize the optics and mounted parts of a number of the ridiculous assortment of weapons.
 * Metal Gear Solid 3: Snake Eater only had silencers as optional parts, but did feature a scene where a young Revolver Ocelot fitted his Single Action Army revolver with a stock. While riding a motorbike, no less. The End's sniper rifle was also modified; a Mosin Nagant with a metal side-folding stock and pistol grip. And of course there's Snake's custom M1911, which he happily burbles about the enhancements to for several straight minutes.
 * Heehee. "Burbles."
 * The Army of Two games make a big point of having a lot of custom weapon options; the second allows you to bash together parts and create unholy frankenguns to your heart's content ("Why yes, my MP5 does have an AK-47 barrel on it").
 * You can also modify your gun camo; golden finishings increase your aggro (read: making enemies notice and attack you more), while proper camo will decrease it.
 * Gears of War is famed for featuring a gun with an underbarrel chainsaw.
 * Black takes this to its logical conclusion, adding parts to guns simply to make them look cooler; the Uzi is a particularly good example, with the actual charging handle immobilized with a RIS rail. So they added a second charging handle on the side.
 * Modern Warfare 2 features a laundry list of accessories including various scopes and reflex sights, underbarrel grenade launchers and shotguns, and a rather more farfetched portable heartbeat sensor. In multiplayer there's even a special perk to let you take two add-ons instead of one.
 * Modern Warfare 2 also features several prominent problems with the guns shown. The TAR-21, for example, is built and deployed with an integral red dot sight that runs off a power source built into the gun; there are ironsights, but they're backups meant for use if the red dot fails for whatever reason. Taking the Red Dot Sight attachment with the TAR-21 will give you the weapon's proper real-life dot sight system rather than the generic dot sight most other weapons in the game get.
 * The original Modern Warfare prominently features the M4 SOPMOD, mostly used during the SAS mission. SOPMOD is, in fact, a weapon customization kit, (SOPMOD stands for Special Operations Peculiar MODification kit) that includes, among other things, a red dot sight, an ACOG scope, an M203 grenade launcher, a suppressor, a laser aiming module, a foregrip, and all kinds of other fun stuff.
 * World at War allowed the player to use rifle grenades with the M1 Garand and the bolt-action rifles; the process shown is actually incorrect, however, since contemporary rifle grenades required the rifle itself to be unloaded and reloaded with special grenade blank rounds.
 * Black Ops contains much of the above, and introduces an underbarrel flamethrower. Also new to the game is the ability to change the color of the lens or dot in the reflex sights, as well as changing the dot to a circle, a cross, or a skull, heart, nuke symbol, etc. You can also paint your personal emblem onto a gun and engrave your clan tags into the receiver.
 * To their credit, the flamethrower attachment is ridiculously short lived, firing a full tank in about two seconds due to the very small size. However, since most of the stuff used in the game wasn't developed until long after the Vietnam war...well.
 * Black Ops also has a nice fix for submachine guns being used without stocks like they are in Modern Warfare 2 - most guns in that category already have a foregrip attached, so adding the Grip attachment typically makes your character unfold the stock instead.
 * Modern Warfare 3 adds the Hybrid Sight, which is a holographic sight with a magnifier that can basically turn it into an ACOG scope with the push of a button. Special mention goes to the version attached to one of the starting weapons of the "Eye of the Storm" mission, which, like the page image, is a sniper scope with a reflex sight attached to it.
 * Battlefield 2142 features a number of modular weapon parts, such as a scope stabilizer for snipers and underbarrel shotgun or grenade launcher for assault troops.
 * Bad Company 2 generally has two variants of each weapon in singleplayer; generally it's either the ammunition or the sight that differs. The assault rifles mount underbarrel grenade launchers, too. In Multiplayer you can customize weapons by yourself. Mostly just red dot and ACOG sights, but also cool gadgets like a scope that automatically marks spotted enemies on the minimap (you normally do this yourself - or, on Hardcore, can't) or buckshot rounds for underbarrel grenade launchers.
 * Battlefield 3 refines gun attachments even more. The barrel, scope, and grips can now be customized to your liking.
 * Dark Sector features a weapon add-on system that allows bonuses to be added to areas like weapon damage or magazine size, as well as weirder options like making the gun fire two bullets at once on each trigger pull or coating bullets in antiviral gas. Abusing the magazine size mods can potentially allow you to fire four shots out of a double-barrel break-open shotgun before reloading. It also features a rather tacticool AKS-74U with a reflex sight mounted on the forend, the world's first sliding underfolding stock, clipped twin magazine, and a silencer.
 * The Trooper Gun is a rocket launcher with an underbarrel pneumatic Gatling gun. Rawr.
 * Return to Castle Wolfenstein had a silenced Sten gun (which did actually exist, but wasn't accurate beyond a couple dozen feet), the Kar 98's scope as a separate pickup, and a very obscure M3 Carbine fitted with a "Snooper Scope," an early active infra-red sight.
 * The 2009 Wolfenstein had extras for every weapon, from the mundane like carrying more ammo, through the utilitarian like loading the Kar 98 with stripper clips instead of single shots (something it should do anyway), to the extremely silly such as building a magazine-fed Panzerschreck that fired homing missiles. Some weren't visible, like shortening the laser gun's charge-up time from one full second to half a second.
 * Resident Evil 4 featured a stat-based gun upgrade system, but some weapon also had add-ons; the Mauser C96 and Steyr TMP had optional stocks, while the rifles and mine thrower had optional sights; the rifles could mount a fixed scope, adjustable scope, or a thermal sight. In addition, almost all the weapons in both 4 and 5 feature a laser sight to provide a third-person aiming point for the player without using a crosshair.
 * The original Killzone had secondary fire modes for the weapons; the ISA rifle had an underbarrel grenade launcher, the Helghast rifle an underbarrel shotgun, and so on. These were removed in the sequel, though the ISA rifle gets a usable EOTech reflex sight instead.
 * In Turok: Evolution, most of the weapons have additional upgrade parts. These include a folding stock, barrel and scope to turn the pistol into a Sniper Pistol, a unit that lets the shotgun fire multiple shells at once, and, ridiculously, an upgrade that lets the wussy flechette gun unfold itself into a triple minigun.
 * The STALKER games feature various weapon modding systems; in the first there were add-on parts (grenade launchers, silencers and scopes); the second included a stat-based system but retained the physical upgrade parts as well.
 * Final Fantasy even got in on this trope, when Dirge of Cerberus rolled along. Vincent is allowed to construct three guns from any combination of parts; there are three main "frames" (respectively being ridiculous mutant triple-barrel versions of a revolver, submachine gun and rifle), each of which can be fitted with a short, medium or long barrel (bearing in mind this is Vince, so the long barrel is four goddamn feet long and even the medium barrel makes Cerberus as big as Vince's leg), a scope or magic booster in one slot, an "option" in another (stat boost) and an "accessory" in a third (a Materia, generally). It's a lot less flexible than it sounds.
 * Halo featured a sniper rifle with a digital scope and the infamous scoped pistol, but the basic rifle had something much stranger; a built-in compass that pointed to the gas giant that the Ringworld orbited. Precisely why the rifle had such a feature is not really clear.
 * The assault rifle also displayed the number of shots it had remaining, which would have been more useful if your HUD didn't also show that.
 * Quake IV featured a primary assault rifle fitted with a scope and tactical light; in addition, many weapons were modified by NPCs during the course of the campaign, with mods including a magazine feed for the shotgun instead of reloading one shell at a time, a scope and lock-on for the nailgun, Chain Lightning for the Lightning Gun, and so on.
 * Far Cry featured several weapons with scopes, a G36 with a scope and underbarrel grenade launcher, and the OICW carbine-automatic grenade launcher combo.
 * In Soldier of Fortune 2 it was possible to select accessories for some weapons; for example, the option of a tactical light or silencer for a pistol, or an optional bayonet on the AK. It also featured the OICW, with an absurdly complex system for using the computerized scope that made it practically unusable. (Truth in Television, allegedly.)
 * Dante's guns Ebony and Ivory in Devil May Cry are heavily customized Colt M1911 pistols with massive top-ported compensators, wood grips, customised slides with side exterior ejectors, and extended magazines with slam pads. The rifle "Spiral" in the third game is a customized Lahti L-39 anti-tank rifle with a shortened barrel, overhead grip and added wooden handguard instead of the usual ski-equipped bipod.
 * One of the preorder DLC bonuses in Just Cause 2 is a custom revolver that actually mounts an underbarrel grenade launcher.
 * However, they at least didn't go completely crazy: the grenade launcher is a 10mm variant, which, while still ridiculous since it doesn't exist, is at least semi-plausible.
 * FEAR has a few tacticool fictional guns, including one that's a Heckler & Koch SL8 with altered sights and a tiny C-Mag. The crowning glory is FEAR 2's pistol, however; in the standard Black tradition, this has a big accessory rail mount covering the whole front of the gun, with top, side and lower mount points. What's on it, you ask? Um, a second set of iron sights and nothing else.
 * Fallout: New Vegas introduces weapon attachments like scopes or extended magazines, although Fallout 2 had a simpler version of the game mechanic.
 * Borderlands features a modular system that is used to procedurally create weapons; there are millions of possible combinations, though with the exception of a few unique guns they were mostly cases of The Same but More, but then their idea of more does include rounds that cause enemies to be electrocuted, burn, be melted by acid or just outright explode.
 * Mass Effect has a VERY extensive system. All weapons are modular and collapsible for easier transport. Additionally, all but one can accommodate one or two "mods": small packages that contain stuff like extra heatsinks, stronger accelerator rails, stronger scopes for sniper rifles, etc. Even bullets have mods like polonium rounds (poisons target and stops regeneration), incendiary rounds, EXPLOSIVE rounds... Mods can be installed and removed in no time (literally, since the game is paused on the inventory screen), even during battle. The right amount of mods and upgrades on guns will make them seem like entirely different weapons. For example, take a Volkov sniper rifle, and put two Scram Rail X mods on it along with an Explosive Rounds X mod. It now overheats after every shot, giving it a very slow firing rate, but it can take out multiple enemies with one hit, and does enormous damage to boss-class enemies, making it more like a rocket launcher than a sniper rifle. Similarly, mounting an Inferno Rounds X mod along with a few heatsink upgrades on a Thunder assault rifle will give it huge damage and capacity, but also somewhat punishing recoil- much like a light machine gun.
 * Mass Effect 3, re-adds gun accessories. The mod system is not quite as complex as Mass Effect 1's, but a hell of a lot more convenient, since you don't have to keep track of hundreds of individual accessories (after you find the accessory once, you're given unlimited copies for all guns of that class). Mods are now assorted by strength from levels I-V rather than I-X now. Things like scopes, bayonets, and piercing mods can be put on the guns in addition to Mass Effect 1 style upgrades the give a flat upgrade to damage or capacity, and you can still equip your guns with various types of specialized ammo. Multiplayer adds another layer to the mod system by allowing you to apply four mods to your guns (two accessories, a specialized ammo type, and a one-use upgrade that enhances damage, decreases recoil, or increases only headshot damage) rather than three.
 * Medal of Honor: Airborne features an experience system where unlocks in the form of weapon modifications are earned by using the weapon in question; these include such addons as scopes, bayonets and extended magazines.
 * Jagged Alliance series has these, especially Jagged Alliance 2 1.13 mod, where almost every accessory listed above is present in the game.
 * One thing that's NOT listed above: Kobra reflex sight that can only be mounted on Russian side rails and fits on Russian assault rifles in game. Also, caliber/length changing barrels, such as AR-15 upper receivers for FN 5.7mm rounds, and EBR stocks for M14 rifles are categorized as "accessories."
 * More modern firearms with Picatinny rails can accept a wider variety of accessories compared to older WW 2/Vietnam War era guns. The EBR stock does exactly that to the M14.
 * Also, while accessories make hitting stuff easier, they do add to the weight of the gun, and mercenaries with weak strength suffer from the weight of the gun by moving slower and getting less shots per turn. Gets quite serious when a fully modified 5.56mm assault rifle can weigh as mush as 15 pounds(7 kilograms) with a C-Mag attached.
 * Brink includes the ability to customize most of the weapons in the game with muzzle breaks, silencers, scopes (both ACOG like tubes and Red dots), Extended Magazines, Drum Magazines and more.
 * 7.62 High Calibre features a heaping helping of gun accessories. Guns are limited in what they can mount both based on their design, and the accessories themselves: some accessories (especially scopes) are designed to fit specific guns, so trying to mount a PSO scope for an SVD sniper rifle on to your M14 won't work. The most versatile accessories are rail-mounted, but they are also invariably more expensive. You can trick out your gun with a silencer, a tactical flashlight, a laser-sight, a scope (true sniper, red dot, or ACOG), an underbarrel attachment like the Masterkey shotgun or grenade launcher, a bipod, and a bayonet. Whether or not you want all that (hint: you don't) is up to you.
 * Metro 2033 features some truly impressive weapon mods right from the get-go. The revolver can actually be modified with a scope, extended barrel, stock and silencer, effectively giving you a silenced sniper rifle as your sidearm! Other weapons, such as the AK-74 and Kalash 2012, only have one or two attachments available.
 * Introduced to Saints Row in the third game are upgrades for weapons that change how they work, most commonly adding explosive, incendiary, or armor-piercing bullets at the highest level. A few guns also mount other accessories such as scopes and flashlights.

Web Original

 * Pimp My Gun is built around doing this.
 * The AR 15 Builder is similar, though it's actually a custom order system for a real gun manufacturer rather than a toy.
 * This site lets you play around with various accessories for a pistol.
 * According to this IMMD entry, a kid managed to make an improvised sight.

Western Animation
"Moe holds up a rifle, attached via strings and rods to four smaller weapons. Moe: And that's how, with a few minor adjustments, you can turn one gun into five guns."
 * Homer Simpson joined the gun club, and was at the meeting.

Real Life

 * In real life, the obsession with accessories often leads to terms like "geardo" and especially "tacticool" being thrown around. And debates still rage on and on as to which accessories are acceptable, but for the most part, if you slap crap on that you're most likely not going to use unless you're a SWAT member or Black Op and aren't intent on murdering anyone but poor practice targets, you'll get laughed at/flamed.
 * Some take it to extremes for kicks, such as the Tacticool Mosin-Nagant below. Yes.
 * 37mm flare launchers are popular as rifle accessories; not because they're even remotely useful, but because it looks like you're a badass with a proper 40mm underbarrel grenade launcher. At least that's the theory, since it's titanically unlikely anyone who actually owned such a thing would attach it to his range toy.
 * In movies, these often play the part of real underbarrel launchers, since they're cheaper, easier to get hold of, and don't require large numbers of murderously expensive destructive device permits.
 * The domestic version of Germany's G36 assault rifle has a dual scope, with one of the eyepieces being a reflex sight and the other a magnifying scope.
 * Combination weapons such as the XM29 OICW and Daewoo K11, make it a little hard to determine which weapon is the main and which is the accessory. The OICW gains bonus points here, since, despite weighing 18 pounds loaded (as much as two and a half loaded M4 carbines), it still had provision for mounting a bayonet.
 * This Pimped Out Pistol is good example, given the silencer would make the giant scope useless unless you have severe problems making shots at ten yards.
 * I'd be more concerned with the fact that the pistol would be impossible to load. Due to the way that the action of the pistol works, when the slide is pulled back to chamber a round, the barrel, and hence the silencer, tilt upwards by a few degrees. This is clearly impossible with the scope flush against the silencer, so to load (and to fire) the pistol one of them would have to be removed.
 * Yup, they went there.
 * The Muzzelite bullpup stock is an accessory stock that you actually shove the entire gun inside; after throwing in a compatible Ruger or Marlin action, you can pretend you have a proper bullpup rifle. One made of cheap plastic with a hideous trigger pull, but that's tacticool for you. These formed the basis of the Morita assault rifles in the Starship Troopers movie.
 * Trench warfare gave the world the Periscope Rifle, a way to lean up and fire over a trench without the annoying part where the dastardly Huns blow your head off your shoulders.
 * How could you insert the Periscope Rifle without mentioning the equally goofy Krummlauf Device? Invented by the dastardly Huns for use against the Britischer pigs, Amerikaners, et.al...
 * Perhaps the silliest are accessories larger than the actual gun. Such as the Cornershot, a pistol (and more recently carbine and single-shot grenade launcher) accessory the size of a full-size rifle that includes a camera and mount and allows the mounted gun to be sighted and fired around corners. Cat accessory optional. Seriously.
 * You knew this would exist, didn't you?
 * At the other end of the cup holder / gun scale, the Battle Mug features standard accessory rails and thus is actually capable of being fitted with rifle accessories, allowing you to at last have a cold one with a reflex sight and taclight.
 * The Tacticool Mosin-Nagant. What has science doooooone?
 * There's a kit that turns a Browning M1919 into a "modern" SAW-style weapon (translation: it looks like it's from the 90s rather than the 30s, has rail sights and a foregrip). Why you'd visit such horrors on one of the relatively small number of transferrable M1919s is somewhat unclear.
 * This may be a contender.
 * The Swedish Army tactical manual outright states that when you load a magazine into your weapon before heading into a firefight, it should have another one duct-taped to it. It also instructs you on how to do it properly.
 * As ridiculous as the idea sounds, some weapons (the SIG SG 550 for example) have magazines designed to be clipped together, and Heckler and Koch even makes a specific accessory that holds two MP5 magazines together (they're about an inch apart) to facilitate speedy reloading. The practice is depreciated for calibres of 7.62x39mm and larger, however, as it adds enough weight to play merry hell with the weapon's balance.
 * This is called "Jungle Style" clipping, which has it's roots in World War 2 with the M1 Carbine. Troopers would tape two magazines together to facilitate faster reloading.
 * Think underbarrel grenade launcher is cool? Try underbarrel shotgun. And yes, they actually use this in real life.
 * One of the uses for such an add-on? Shooting out the locks on doors. Or, more accurately, shooting the door off of the lock, allowing it to be easily kicked open, hence the marketing name for the original such add-on: The Master Key.
 * The Israeli Galil assault rifle has two accessories, both built into the bipod. The first is a wirecutter. The second is a bottle opener. The second may sound strange, but among the civilian reservists serving in the IDF a wide-spreading habit had them popping the tops off of soda bottles with the rifle's magazines, which damaged them.