"Kill! Kill! Kill!"
It's not the size of the gun that matters, but rather, it's ability to remove your head.
Revolver Pistols Revolvers are handguns (And occasionally rifles) that utilize a revolving chamber. To put it simply, these weapons can fire repeatedly because they have a revolving cylinder that can hold multiple rounds. After one round is spent, by one means or another, the next round rotates into place, and it can be fired just like the first was. Commonly, these cylinders hold anywhere from four rounds to eight. Revolvers are often known because of their louder report, and the fact they commonly fire rounds with a higher grain-count (and therefore higher power) then semi-automatics. Revolvers come in many varieties, the main difference usually being their method of reload. The three most common types of reload are gate load, break-barrel, and side load. Gate loads feature a single opening through which every shell may be loaded one at a time, without removing the cylinder. Break-barrels feature a hinge on the bottom of the cylinder, allowing one to "crack open" the gun and load from the back of the cylinders. Side loads let the user swing the cylinder off to the side, load it, and lock it back in place.
Semi-automatic pistols Semi automatic pistols are pistols that have the capability to fire a rather large number of rounds without the need to manually operate any mechinism to chamber rounds. In lamens terms, this means they are pistols that will fire every time you pull the trigger. This is because of the utilization of a spring loaded magazine. After firing one round, the cartridge is ejected, and a new one is loaded into the chamber automatically. Every time you pull this trigger, the action is repeated. There are many varieties of semi-automatics, and magazines commonly hold 8 to about 18 rounds. (10 is the standard)
Machine pistols The machine pistol is fundamentally very much like a semi-automatic pistol, mirroring it's basic look and feel, along with it use of the magazine. However, machine pistols are fully automatic. If you hold the trigger down, it will automatically expel every round in the chamber rapidly. This is because the automatic action uses the force of recoil to help reload another round (like the semi-auto), however, unlike the semi-auto, it also utilizes this force to fire another round. Machine pistols, as a general rule of thumb, carry more ammo in their magazines then semi-autos or revolvers, commonly ranging anywhere from 12 to 32 rounds. (Around 20 is most common)
Muskets Primitive arms fired from the shoulder, with long barrels and (mostly)no rifling are considered muskets. Any muskets found in the wasteland will almost certainly be homemade post-war arms. This is a blanket term, referring to arquebus, flintlock, wheellock, and matchlock weaponry. All Muskets are loaded from the muzzle, and musket balls must be pushed down (After emptying powder)with a ramrod. Basic muskets take long periods of time to load (About 20 seconds), and are only accurate around about 50 Feet. A more advanced musket incorporating a rifled barrel, and cartridged shot, is accurate to about 100 feet, and loads far quicker.
Rifles: Rifles are the musket's younger but much tougher brother. Rifles are named after the quality of their barrels, which are 'rifled'. Rifled barrels are barrels that have groves curving all the way down the barrel. These grooves give the bullet spin, which offers far more stability when flying through the air, and far more range. Another improvement is their use of cartridge, which allows far faster reloads. Rifles are usually bolt action, muzzle loaded, or semi automatic. Bolt action rifles require the user to manually cock a bolt to load cartridges into firing position. Muzzle loaders are loaded from the barrel, and I hope you already know what a semi-automatic is.
Shotguns: Shotguns, like rifles, are relatively long barreled and in most cases fired from the shoulder. However, they feature no rifling, and do not fire cartridges like most of the other weapons you've encountered so far. Shot guns fire 'shot' which is the name for multiple small lead pellets. Shot is kept within large shells, and is deadly effective, spreading your kill zone out, and doing far more damage then a single bullet. The use of shotguns varies quite widly. Some shotguns, with well maintained, rather long barrels, are fairly accurate, and focus on making as many holes in one target as possible. Others, sawn-off, or specialized, are simply designed to spread as far as possible as quickly as possible, making it a brutal weapon up close and against crowds. The shotgun excels against creatures, but is deadly against humans as well.
"Assault" rifles: The assault rifle is generally a military weapon, designed to kill other human beings. And it does so effectively. Assault rifles is a generalized term, and doesn't actually specifically designate any type of weapon, but they do fit into some vague classifications. Assault rifles, as you've probably assumed, are, in fact, shoulder fired rifles, holding the range and stopping power of it's cousin. However, much like machine pistols, assault rifles are fully automatic. They commonly feature magazine of 20-50, and are deadly effective in the wastelands. The assault rifle is often the best case scenario when facing other humans, and is still a good option against animals.
Minigun Multiple barreled weapons designed to chamber and fire ammunition by use of rotational firing pins and mechanisms. These weapons can achieve a very high rate of fire (up to 60,000 rounds per minute.) The barrels rotate and are typically air-cooled, requiring a small cool-down period after extensive firing sessions. They are based on the Gatling Gun design, cranked up to eleven. There is a delay in time between pulling the trigger, which must be held down, and the actual firing of the gun, so this must always be taken into account.
Machine Gun A machine gun is a portable or mounted weapon designed to fire cartridges in rapid succession, typically from a belt or box magazine. The weapon’s RPM can differ from anywhere between 600 and 1,200. Machine guns are often divided into Heavy, Light and General Purpose. Each has its own pros and cons, with the light being weaker but portable and the heavy being (obviously) heavy and typically mounted to a vehicle. The general purpose combines these two, without being perfect. Usually air-cooled, but water cooled is not unheard of for a heavy machine gun.
Flamethrowers (Flamers) A device used to spray a continuous stream of flammable gels or liquids. The gel or liquid is set alight from a pilot light at the nozzle of the weapon. A flamethrower consists of a firing mechanism and tank for storing the liquid. The liquid is pumped out of the nozzle of the weapon where it is lit by the igniter, causing a stream of deadly hellfire.
Missile Launcher A missile launcher is a shoulder fired weapon that is light enough for a single person to carry. It is usually a tube that contains a rocket propelled projectile. The missile is launched from the tube by a charge (which varies depending on the weapon) until it is a safe distance away from the operator where the rocket on the projectile activates, taking the missile the rest of the way to the target. They are extremely powerful but can be inaccurate at times. Ammo is rare and precious.
Grenade Launcher A weapon designed to throw a grenade more accurately and farther than a human could by hand. These can come in the form of a stand-alone weapon or an attachment for under the barrel of a rifle. Usually a shoulder fired weapon with a revolving or crack open loading system. They fire one of the widest variety of shells of all weapons, including frag, smoke, teargas, incendiary, non lethal and many more. Great care must be paid to distance; otherwise you may end up on the business end of your own explosion.
Homemade explosives: Sometimes it’s as simple as a tube filled with scavenged gunpowder lit by a fuse and sometimes it is as complex as a proximity bomb using microwave technology. Never underestimate the many ways to build an explosive.
Even the most simple wastelander can build the Molotov Cocktail. A glass bottle filled with flammable liquid and a rag soaked in said liquid . Hold the rag in place with the bottle’s stopper, light and throw. Watch the world burn.
Grenades: A grenade is quite simply an anti-personal weapon that is thrown and explodes a short time after release. What it does when it explodes depends on the type of grenade you throw. Frag grenades explodes into many sharp pieces of shrapnel, Flashbangs make a loud noise and blinding light to stun opponents, Incendiaries are designed to release waves of flame. Concussion grenades are likely the most common variety in the wasteland, and they work by pure concussive force, rather then flying shrapnel or other tricks.
Usually has some kind of pin you pull to activate it before tossing. You can ‘cook’ the grenade by holding it longer before throwing to give it a shorter time before explosion.
Some special grenades are fired from rifles. Either placed on the barrel and then propelled by a blank cartridge, or fired from a special under the barrel launcher it’s a convenient way to turn a rifle even more deadly.
Landmines: These have been considered some of the most dangerous inventions in Warfare because they stay active long after conflict has ended, killing any random wastelander unlucky enough to step on it. Sometimes even the person who set it will walk across.
Normally used as a tactical barrier to defend a position, they can sometimes be set in offensive positions, such as a well know supply route to sever resources. The boldest of the bold may even take to throwing these devices much like a frisbee.
Anti personnel mines are the most common but the Anti-Tank mines is the bigger, badder version designed to remove the treads or pierce the thick armor of a prewar tank. Luckily the pressure pad on these are too strong for a human to set off, but with enough skill that could easily be changed.
Laser weaponry: Weapons just starting to come into the mainstream before the war, Laser rifles and pistols aren't as rare as one might expect, although they are considerably more rare then most conventional arms. Rather then firing conventional bullet, one loads an electron charge pack or energy cell into the firearm, and it sends out large unfocused bursts of heat and light. It is focused though a series of well honed and designed lenses, and comes out as a small, deadly, concentrated beam, fully capable of turning foes to piles of ash.
Plasma weaponry: Plasma weaponry is rare, unique, and powerful. Using the same cartrages as laser weapons, these foreign looking objects instead use the energy to produce and hurl powerful green blasts of a superheated substance known as plasma. While far slower then a energy beam, and a bit slower then a bullet, it makes up for it with killing power. It can reduce enemies to piles of goo. Just be sure not to eat it, because it sure as hell doesn't taste like jelly.
Magneto weaponry: Specially designed military hardware. While magneto weapons may look more like small guns then energy weaponry, they are easily detached enough from their conventional cousins to be right at home with laser rifles. Using powerful electromagnets along their barrels, or sometimes as their barrels, Magneto weapons fire rounds at ridiculously high speeds with huge amounts of penetrative force. Most use the same general loading mechanisms as normal rifles, although the bullet picks up speed by traveling through the barrel, rather then being propelled through it. While they look rather like normal rifles, their barrel usually features strange, often octagonal or square, 'fans'. These are the magnets that actually propel the rounds. Because of it's great speed and therefore penetrating power, magneto weapons often fire surprisingly small calibers of ammo. This is very deceptive, and while most wastlanders will laugh, seasoned veterans or knowledgeable travelers will steer clear.
Tesla and pulse weaponry: The rarest of a rare category of weaponry, Tesla and Pulse rifles are usually only seen in the hands of the real heavy hitters in the region. Pulse weaponry is sometimes confused for more common laser weaponry, because of it's similar traits and appearances. However, Pulse weaponry uses strange munitions, and is often thousands of times more complex when the weapons faceplate is taken off. Designed to punch through mechanized units, pulse weapons are sure to get the job done when dealing with robots, vehicles, or power armor.
Tesla weapons are extremely rare and foreign, and are sometimes waved off as mere rumors. Wielded much like heavy weaponry, these large weapons fire bursts of so called "chain-lightning". Be careful. If you're the only thing in the area, it'll likely come back to kill you.
Melee Weapons that are built for close combat and nothing else. You have to get close to use these but if you can they’re extremely effective.
Slashing These weapons are used to create gashes and wounds in the body of the victim by large cutting motions. Curved blades are particularly great for this and the blades do not need to be long to inflict massive wounds. The best blades are curved and thick, sharpened at one edge. Double edged blades run the risk of harming the user.
Stabbing These weapons inflict wounds by penetrating the skin and clothes of the victim. The best blade type is long and thin, typically two sided and double edged, through a round or three-sided blade with no edge is also common and effective. The best part about these weapons is that they don’t have to be sharp: only pointy. They can be found almost anyway and are very deadly.
Crushing Weapons that are blunt and heavy. They kill by crushing the bones and organs into mush. Heavy and dull blades sometimes fall into this but normally a crushing weapon has no edge. These are the most common of all melee weapons being readily sold by merchants or found in the environment.
Bows A bow is a weapon which fires a projectile (typically an arrow) using the elasticity of a string which is stretched between two limbs. When the bow is drawn back, energy is stored in the string and when the string is released the arrow flies forward with great power. These weapons require great strength to use and much practice to become accurate with.
Thrown weaponry Simple as a rock thrown from the hand or a spear thrown from an atlatl. These are simple to find and make. Typically spears can also double as throwing weapons. The impact of these weapons can often knock a man off his feet or into unconsciousness. Do not underestimate a well-thrown rock.
A sling is simple. A small pouch between two lengths of rope. The two ropes are held in the hand and then the sling is swung in a circular motion above the head. One of the two ropes is released during spin and the rock in the pouch flies toward the target with great speed, much farther than could be thrown by hand. They are very easy to build and inexpensive to make. However, they are one of the more difficult weapons to use effectively for hunting or battle requiring significant and sometimes years of practice to become proficient.
The slingshot is different. It is a Y shaped structure, held in the hand with a length of rubber or elastic cord attached to the uprights. A pouch is held between the cords and the projectile is placed within. The cord is pulled back and let go, firing the projectile from the pouch. These can be made with simple material but some were manufactured pre-war and are very powerful. It’s easy to laugh at a slingshot until your missing a chunk of your head.