This is the official /k/ Sticky. It is suggested that you read all of the information here (as well as the Disclaimer) in full. This sticky is really a compilation of information; none of the information on this page is original content. The original author will not be cited, since it is too much work. However, if you want source, just google part of the passage and you'll probably find it.
See: Gun Safety Rules for more detailed information.
Gun safety is a collection of rules and recommendations that can be applied when possessing, storing, or handling firearms. The purpose of gun safety is to eliminate or minimize the risks of unintentional death, injury or damage caused by improper possession, storage, or handling of firearms. Therefore, four major rules have been universally recognized.
Jeff Cooper, an influential figure in modern firearms training, who praises the CZ-75 as the pinnacle of handgun designs, formalized and popularized "Four Rules" of safe firearm handling:
- All guns are always loaded.
- Never let the muzzle cover anything you are not willing to destroy.
- Keep your finger off the trigger until your sights are on the target.
- Be sure of your target and what is beyond it.
If you have any questions about what a word means when pertaining to firearms, check these two links before posting a question!
Firearms Actions ExplainedEdit
Bolt Action.EditThe Bolt Action Rifle is a manual-operation firearm. Specifically, this means that after each pull of the trigger, the operator has to pull back the bolt, which releases the spent casing, and push it forward again, loading a fresh cartridge into the breech. The rifle is once again ready to be fired. Bolt Action Rifles are usually seen storing their ammunition in either an internal, non removable magazine, or an external, detachable magazine.
Break Action.EditThe Break Action Rifle is another type of manual-operation firearm. It is usually seen in shotguns, with two barrels, either in a side-by-side or over-under configuration. To load the firearm, a latch is activated, which releases the barrel assembly to be swiveled away from the receiver, allowing the breech to be exposed. Shells are inserted into the breech and the mechanism is closed and latched. Then, the hammer is pulled back and the weapon is now ready to fire by squeezing the trigger. After firing, the break action is unlatched and the barrel and forearm are allowed to fall forward. This will cause a spring-loaded extractor to automatically remove the spent shell. The weapon is now ready for a new cycle.
Pump Action. Edit
Nearly all pump-actions use a back-and-forward motion of the forend to cycle the action. The forend is connected to the bolt by one or two bars. The motion of the bolt back and forth in a tubular magazine model will also operate the elevator, which lifts the shells from the level of the magazine to the level of the barrel.
Before firing a round, the bolt is unlocked and the forend is free to move. The shooter pulls back on the forend to begin the operating cycle. The bolt unlocks and begins to move to the rear, which extracts and ejects the empty shell from the chamber, cocks the hammer, and begins to load the new shell. In a tubular magazine design, as the bolt moves rearwards, a single shell is released from the magazine, and is pushed backwards to come to rest on the elevator.
As the forend reaches the rear and begins to move forward, the elevator lifts up the shell, lining it up with the barrel. As the bolt moves forward, the round slides into the chamber, and the final portion of the forend's travel locks the bolt into position. A pull of the trigger will fire the next round, where the cycle begins again.
Most pump-action firearms do not have any positive indication that they are out of ammunition, so it is possible to complete a cycle and have an empty chamber.
Lever actions are mostly equipped with tubular magazines. They are either fitted with a spring-loaded plunger mechanism that holds the loaded cartridges in place, or a simple rotating shroud. To load cartridges into a tubular magazine, find the release mechanism that will either rotate a small shield, revealing a port in the tube to allow the insertion on new cartridges, or that will release the plunger which should be removed, similarly revealing a loading port. After loading the magazine, close the rotating shield or re-insert the plunger.
Cock the rifle by pulling down the lever and then pulling it back up. Be sure to move the lever through its full range of motion to ensure that the action is fully cycled.
Pull the trigger to fire the rifle. To fire again, you will have to cock it again, in between each shot. Once you pull it down, it ejects the last spent casing, and pulling the lever up prepares the next shot.
Semi-automatic rifles may be operated by a number of mechanisms, all of which derive their power from the explosion of the powder in the cartridge that fires the bullet. Widely used mechanisms include:
In "simple" blowback operation, the bolt isn’t mechanically locked at the moment of firing. The bolt is relatively massive and is kept forward by spring tension alone. At the point of ignition, expanding gases push the bullet forward through the barrel while at the same time pushing the case rearward against the bolt. The empty case is ejected as the bolt travels to the rear. The stored energy of the compressed action spring then drives the bolt forward. A new cartridge is stripped from the magazine and chambered as the bolt returns to its in-battery position. This simple design is mainly seen in firearms designed around relatively low-power cartridges, where spring tension and the mass of the bolt (or slide) are sufficient to keep the bolt forward until chamber pressures have receded to a safe level.
For more powerful rounds or for a lighter operating mechanism, some system of "delayed" or "retarded" blowback is often used, requiring the bolt to overcome some initial resistance while not fully locked. This allows more time for chamber pressures to subside. Once this resistance is overcome, these actions function identically to "simple" blowback action.
- Gas Piston
Gas piston operation uses the high pressure gas ported from the barrel to drive an enclosed piston back against an operating rod, which in turn unlocks the bolt and drives it rearward, ejecting the spent case and cocking the hammer or striker spring. The bolt moving rearward also compresses a recoil spring which returns the bolt forward, stripping a fresh round from the weapon's magazine and forcing it into the chamber.
- Direct Impingement
The tube carrying the high pressure gas ported from the barrel emerges inside the action of the rifle, where it hits the bolt directly and pushes it back, cycling the action. Note that the AR-15, despite often referred to as a direct-impingement rifle, doesn't qualify under this definition, because the gas is not impinging on the boltface. Instead, it mates up with a "gas key" which is integral to the bolt carrier. Thus, the AR is in fact uses a short-stroke piston system, but one in which the bolt carrier itself functions as a piston.
- Short-recoil Operation
Short-recoil operated arms operate by using the recoil of the bolt and barrel to cycle the firearm. The barrel is locked to the bolt and travels a short distance rearward with it until it unlocks, allowing the bolt to continue rearward in its cycle. The bolt moving rearward compresses a recoil spring which returns the bolt forward, stripping a fresh round from the weapon's magazine and forcing it into the chamber. As the bolt returns to it's original position, the barrel and the bolt once again lock together.
- Long-recoil Operation
Long-recoil operated arms operate similarly to short-recoil operated arms, except that the barrel is locked to the bolt until they reach their rearmost position. The bolt is then held in position until the barrel returns completely forward. The bolt is then released and forced closed by its recoil spring, chambering a fresh round.
History of FirearmsEdit
- 1364 - First recorded use of a firearm.
- 1380 - Hand guns are known across Europe.
At this time, guns were fired by holding a burning wick to a "touch hole" in the barrel igniting the powder inside.
- 1400s - The matchlock gun appears.
With this innovation, a shooter uses one hand for firing, and a prop to steady the gun. The first device, or "lock," for mechanically firing a gun is the matchlock. Powder is held in a "flash pan," and ignited by a wick, or match, in a movable clamp. Both hands remain on the gun, vastly improving aim. Early matchlock guns are extremely rare.
- 1498 - Rifling principle is discovered.
- 1509 - Invention of wheel lock (rose lock).
The next major advance, the wheel lock, generates a spark mechanically. With no wick to keep lit, the wheel lock is easier to use, and more reliable than the matchlock. However, wheel locks are expensive to produce. Matchlocks, at half the cost, remain in common use. This is an early (ca. 1540) multi-shot, wheel-lock pistol, made for Emperor Charles V. In this weapon, two locks are combined in one mechanism, to give each barrel separate ignition.
- 1540 - Rifling appears in firearms.
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis. This spin serves to stabilize the projectile, improving its aerodynamic stability and accuracy.
- 1630 - The first true flintlock.
The flintlock solved a longstanding problem. Some time in the late 1500s, a lid was added to the flash pan design. To expose or protect the powder, the lid had to be moved manually. The flintlock mechanism was designed to push back the lid and spark a flint at the same time. The flintlock ignition system reigned for two centuries, with virtually no alteration.
- 1825 - Percussion-cap guns are in general use.
The percussion cap was the crucial invention that enabled muzzleloading firearms to fire reliably in any weather. This was significant because a flintlock was prone to misfire in wet weather. The percussion cap is a small cylinder of copper or brass with one closed end. Inside the closed end is a small amount of a shock-sensitive explosive material. Pulling the trigger releases a hammer which strikes the percussion cap and ignites the explosive primer. The flame travels into the gun to ignite the main powder charge.
- 1835 - The first Colt revolver.
Samuel Colt developed the first mass-produced, multi-shot, revolving firearms. Various revolving designs had been around for centuries, but precision parts couldn't be made with available technologies. Additionally, his design was the first to employ an indexing system, which automatically aligned the next chamber with the barrel as the hammer cocked. Colt was the first to apply Industrial Age machining tools to the idea. Mass production made the guns affordable. Reliability and accuracy made the Colt a favorite of soldiers and frontiersmen.
- 1840 - Guns begin to use pin-fire cartridges.
A pinfire cartridge is an obsolete type of metallic firearm cartridge in which the priming compound is ignited by striking a small pin which protrudes radially from just above the base of the cartridge. Its history is closely associated with the development of the breechloader which replaced muzzle-loading weapons. Pinfire cartridges were convenient in that they could contain percussion cap, powder and shot in a neat pre-loaded package which was several times faster to fire and reload and was inherently safer.
- 1850 - True shotguns in common use.
In the second half of the 18th century, musket design branched out. This period produced a number of single-purpose firearms. The forerunner of modern shotguns was the fowling piece, developed specifically for hunting birds. Among the upper classes, fowling was a leisure sport. Fowling pieces for the very affluent were often lovely works of art, but impractical for hunting.
- 1851 - First effective double-action revolver.
In a double-action (DA) revolver, the stroke of the trigger pull generates three actions: (1) the hammer is pulled back to the cocked position (2) while the cylinder is being indexed to the next round, and then (3) the hammer is released to strike the firing pin. Thus DA means that a cocking action separate from the trigger pull is unnecessary; and every trigger pull will result in a complete cycle. This allows uncocked carry while also allowing draw-and-fire using only the trigger. A longer and harder trigger stroke is the trade-off, but this drawback can also be viewed as a safety feature, as the gun is safer against accidental discharges from being dropped.
- 1859 - The first full rim-fire cartridge.
A rimfire is a type of firearm cartridge where the firing pin strikes the base's rim. The rim of the rimfire cartridge is essentially an extended and widened percussion cap which contains the priming compound, while the cartridge case itself contains the propellant powder and the projectile. While many other different cartridge priming methods have been tried since the 19th century, only rimfire and centerfire technology survive today in significant use.
- 1860 - Spencer repeating carbine patented.
Introduced at the start of the Civil War, Spencer repeating guns were technically advanced, used cartridges, and could fire 7 shots in 15 seconds. But the Army didn't want a repeating gun, fearing that soldiers would fire more often, constantly need fresh ammunition, and overtax the supply system. But in 1863, President Lincoln test-fired a Spencer. His approval led to the purchase of 107,372 Spencer repeating carbines and rifles (of 144,500 made), and the Spencer became the principal repeating gun of the Civil War.
- 1862 - The Gatling Gun is invented.
The Gatling gun is one of the best known early rapid-fire weapons and a forerunner of the modern machine gun.The Gatling gun's operation centered on a cyclic multi-barrel design which facilitated cooling and synchronized the firing/reloading sequence. Each barrel fired a single shot when it reached a certain point in the cycle, after which it ejected the spent cartridge, loaded a new round, and in the process, cooled down somewhat. This configuration allowed higher rates of fire to be achieved without the barrel overheating.
- 1869 - Center-fire cartridge introduced.
A centerfire cartridge is a cartridge with a primer located in the center of the cartridge case head. Unlike rimfire cartridges, the primer is a separate and replaceable component, allowing these cartridges to be reloaded with new powder, bullet, and primer, and reused.
- 1873 - Winchester rifle introduced.
Winchester rifles were affordable, and produced in such great numbers, that the Winchester became the generic rifle. The Winchester had such a powerful hold in some regions that it actually became known as "the gun that won the West." In 1887, Winchester came out with their first repeating shotguns. The next major milestone for Winchester came in 1903, when the company introduced the first automatic rifle that would become widely used. *
- 1879 - Lee box magazine patented.
The most popular type of magazine in modern rifles and handguns, a box magazine stores cartridges in a column, either one above the other (single-stack) or staggered zigzag fashion(double-stack). As the firearm cycles, cartridges are moved to the top of the magazine by a follower driven by spring compression to either a single feed position or side-by-side feed positions. Box magazines may be integral to the firearm or removable.
- 1892- Advent of automatic handguns.
The first automatic pistol was created by Joseph Laumann in 1892. But the Borchardt pistol of 1893 was the first automatic with a separate magazine in the grip, and this remains the defining feature of the breed. More automatics came in rapid succession, including Browning, Luger, Mauser, and Colt models. By the turn of the century, just 8 years after Laumann, automatics were firmly established.
- 1900 - Historical firearms period concludes. Contemporary period begins.
Gun politics addresses safety issues and ideologies related to firearms through criminal and noncriminal use. Gun politics deals with rules, regulations, and restrictions on the use, ownership, as well as distribution of firearms. Gun control laws and policy vary greatly around the world. Some countries, such as North Korea, China, the United Kingdom or Germany, have very strict limits on gun possession while others, such as Yemen and the USA, have relatively lenient limits.
Gun Laws in:
If your country is not listed, go here: http://www.gunpolicy.org/firearms/region/
USA Gun Laws at A GlanceEdit
- The Second Amendment to the United States Constitution:
A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed.
A well written, unbiased look at Amendment II and the court cases which changed its meaning: http://www.law.cornell.edu/wex/second_amendment
- What is this NFA thing I keep hearing about?
NFA refers to the National Firearms Act which is legislation passed back in 1934. It regulates the ownership of certain types of firearms and firearm accessories including machine guns, short barrel rifles, suppressors, short barrel shotguns, destructive devices and a group of items called "any other weapons". All these devices have therefore become referred to as NFA items.
These items have never been illegal at the federal level. However, states can (and do) have their own separate laws regulating ownership and use of NFA items. For example, some states prohibit the ownership of suppressors. Suppressors are legal in Georgia and the devices are legal to use for target shooting but are illegal for hunting. Thus, you should check with your local laws regarding possible ownership and use restrictions.
- What's the AWB?
The Federal Assault Weapons Ban (AWB) of 1994, a federal law in the United States that included a prohibition on the manufacture for civilian use of certain semi-automatic firearms, or so called "assault weapons". The 10-year ban was passed by Congress on September 13, 1994 and repealed in 2004. In the former U.S. law, the legal term assault weapon included certain specific semi-automatic firearm models by name (e.g., Colt AR-15, TEC-9, non-select-fire AK-47s produced by three manufacturers, and Uzis) and other semi-automatic firearms because they possess a minimum set of cosmetic features, such as a semi-automatic rifles able to accept detachable magazines with a folding or telescoping stock and Pistol grip. http://en.wikipedia.org/wiki/Federal_Assault_Weapons_Ban
- Brady Handgun Violence Prevention Act
The "Brady Act" instituted federal (NICS) background checks on firearm purchasers in the United States. It was signed into law by President Bill Clinton on November 30, 1993, and went into effect on February 28, 1994. The Act was named after James Brady, who was shot by John Hinckley, Jr. during an attempted assassination of President Ronald Reagan on March 30, 1981.
- The ATF
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is a federal law enforcement organization within the United States Department of Justice. Its responsibilities include the investigation and prevention of federal offenses involving the unlawful use, manufacture, and possession of firearms and explosives; acts of arson and bombings; and illegal trafficking of alcohol and tobacco products. The ATF also regulates via licensing the sale, possession, and transportation of firearms, ammunition, and explosives in interstate commerce.
- CCW laws
Concealed carry, or CCW (carrying a concealed weapon), refers to the practice of carrying a handgun or other weapon in public in a concealed manner, either on one's person or in proximity. In the USA, one would need a permit to CCW. To learn about CCW laws in the USA, (since they are state-regulated and not federally regulated), check out:
- FFL (Federal Firearms Licenses)
A Federal Firearms License (FFL) is a license that enables an individual or a company to engage in a business pertaining to the manufacture of firearms and ammunition or the interstate and intrastate sale of firearms. There are different kinds, such as a type 1, type 3, etc. Check out the kinds here: http://en.wikipedia.org/wiki/Federal_Firearms_License
How to become an ffl: http://www.atf.gov/firearms/how-to/become-an-ffl.html
How to get guns when you are a baguette (French's law) Edit
Okay, here we go, french cuckoldry is really heavy, it's gonna be clear : You don't even have the right to carry a pepper spray in your bag ! It's not a joke !
So, if you don't want to desert during the near-coming civil war, here is how to do :
- 1) You are a muslim, just call Mohamed and get your AK on inside the mosque...
- 2) You are white and here it's more complicated :
Cat. D : Free access for 18+ Edit
The most powerful thing you can buy and carry only at home is a black powder weapon made before 1900. It's often .44 (for shooting horses...) or .36 (this one is better for penetration).
The "best" gun you can buy is a Remington 1858, I have a .36 caliber and ogival paper-made cartridge.
The worse issue is that black powder doesn't come with ammunition, you need to do them by yourself. You take black powder, light paper for smoking and a fire-making component (amorçe).
You can have the lower price for 300€, do not buy the "laiton" case, it's too weak, buy the steel one !
REMEMBER YOU NEED A MEDICAL CERTIFICATE FOR GETTING A LICENSE !!
Cat. C & B : You need to try not to act autistic when visiting the medic... Edit
If you want a "real" gun, here is what you need :
- 60€ : Ball-trap license (cat. C)
- 50€+100€ : Hunting license (cat. C)
- 200€ : Shooting license (cat. C + B)
On category C you have those calibers only in bolt-action : .22Lr, .222, .308Win, 30-06 Springfield, and the most powerful is .338 Lapua. Do not forget that it's only bolt-action and it's maximum 9-rounds + 1 cartridge holder !
The most interesting thing on category C : the shotgun ! Actually it's not a real shotgun because the barrel is made like a carbine (it's rifled). Here are some good weapons : Remington 870 Express & Mossberg Maverick 88 & Fabarm STF12 (but it's really pricey ~1300€)
Cat. B : It's the beginning of serious stuff here Edit
Remember you need a shooting license (minimum 200€)
So here, you can get handgun, 9mm, .45ACP, .357 and all that stuff
You can get a semi-automatic rifle, 7.62x39 and 5.56, all those "war calibers"...
REMEMBER YOU NEED A MEDICAL CERTIFICATE FOR GETTING A LICENSE !!
Choosing a Gun to PurchaseEdit
The first firearm purchase for a new gun owner should be a .22 rifle. Some reasons include:
1. The .22lr cartridge is low recoil. Low recoil allows you to shoot all day long without pain, discomfort, or generally wearing you out. With many things, practice makes perfect, and low recoil allows you to practice more. It also makes you more inclined to go to the range more often.
2. The .22lr cartridge is cheap. Cheap means you can buy lots of ammo at once, instead of buying "a few boxes on the way to the range" thus hurting your wallet, and limiting your range time. Even the "good stuff" (CCI mini-mag) is currently $8.50 for a box of 100 rounds. If you have a bolt action, you can even use the "cheap stuff" with no worries ($15 for a brick).
3. The .22lr cartridge is plentiful. There is a low chance of the .22lr becoming obsolete,
hard to find, or banned.
4. The .22lr cartridge is "range friendly". Even the most restrictive of indoor shooting ranges do not hesitate to allow the use of a .22.
5. The .22lr has a low report. If you live a few miles away from anyone, you can setup a range in your back yard and plink without paying any range fees. Research your local laws on this!
6. The five above items make the .22lr FUN! If you aren't having fun, its a chore. Chores are usually put off, forgotten, or abandoned. Fun means you do it more often.
All these reasons make the .22 rifle the best FIRST gun since only with practice, training, and more practice, can you learn MARKSMANSHIP. There are many sayings about this: You can't miss fast enough to hit your target, You can't miss enough times to get a hit. Only hits count.
The .22 rifle should not be the ONLY gun, just the FIRST. There is plenty of time and money to buy other specialized guns later, but this one is specialized for target shooting, small game, all day shooting, and fun.
Buying a handgun can be a dizzying ordeal. The popularity of them ensures that you have enough choices to make your head spin, with prices ranging from an expensive lunch to a used car.
For as many handguns as there are, surprisingly few become truly popular. But they are popular for a reason, so start narrowing down your choices and preferences by examining popular models. Smith & Wesson, Glocks, HKs, Sigs, CZs, Berettas and Rugers. There are tons more, but don't get ahead of yourself.
Pick a frame size first. Full size handguns generally offer longer grips, higher capacity magazines and longer barrels. Semi-compacts usually still have long enough grips that fingers aren't left without purchase, they accommodate fewer rounds (usually 2-3 less) and have shorter barrels. Compacts usually have very short grips for easier concealment, even fewer rounds and even shorter barrels. Pocket guns are very small, very thin, nearly always single stack, with very short barrels. Grip diameter will almost never differ between different frame sizes of the same model.
Ergonomics are somewhat difficult to nail down, because when you pick up a gun you "like," you're going to WANT to like it and you may overlook its flaws or uncomfortable features. Try some prospects out, use popular, readily available handguns as a springboard to decide what you do and don't like. Be critical. Does it hurt your hand someplace? Do all your fingers have purchase? Can you reach the controls? Can you manipulate the slide? Does your resting thumb prevent the slide stop from working? Can you reach the magazine release?
After you've handled or at least researched some, take the list of features and requirements you like and narrow down your options further. Maybe one of those popular guns is your baby girl. Maybe one's very close but you'd prefer a parallel option. Maybe you're a hipster and want to carry a Dardick 1500 because I'm sure you've never heard of it before. Finding what you want is the easy part, it's knowing what you want that's hard.
Why no revolvers? Because we're lazy.
Gun Buying GraphicsEdit
How to buy Firearms online in the USA Edit
Each website has its own policies when selling you firearms, but long story short:
- You buy it online
- You submit the info of a local FFL (usually a gun store/pawn shop/etc) of your choice to them
- They ship it to the FFL
- You pay FFL handling fee
- You get gun
Some good places to buy (probably forgot a few):
- odcmp.com (Civilian Marksmanship Program; can sell M1 garands and other US surplus rifles straight to your doorstep)
Ebay/craigslist-type websites for firearms:
To find ammo for the lowest price, check gunbot.net frequently.
See: The AR-15
Poorfag Guns Edit
Got $300? Good, here are some cheap guns to buy that are of decent quality.
Choosing A Knife To Purchase.Edit
A Multitool is Kind Of A Knife... Right?Edit
A multi tool is basically a pair of pliers with other useful tools that can be accessed from the handles. The concept was invented by Tim Leatherman while he was traveling through Europe. He found Swiss Army Knives lacking for his heavier duty work and developed a tool that included a good pair of pliers, as well as other things you would expect to find in a Swiss Army Knife: screwdrivers, a knife and a can opener. Other companies before him had made similar tools on a much smaller scale, but Leatherman brought multi tools to the masses. 25 years later, Leatherman is still the market leader. The biggest difference between multi tools and Swiss Army Knives is still the pair of pliers. Some Swiss Army Knives have pliers, but they are only useful for small jobs.
Survival In The WoodsEdit
- SAS Survival Handbook
- FM 21-76, AKA Army Survival Manual
- FM 4-25.11 AKA Military First Aid
- Army Ranger Handbook
- USDA Home Canning Guide
Gas Masks Edit
Many people buy a gas mask to keep around, either for aesthetic reasons or to prepare for possible gas attacks. However, there's a lot of misinformation about gas masks, and purchasing and wearing a surplus gas mask without doing your research can result in serious medical issues like lung cancer.
Old gas masks were made with carcinogenic materials like asbestos. Don't just buy any old surplus mask that looks cool and breathe through it--you could be putting yourself at risk of lung cancer. Instead, research the specific model of gas mask before you put it on. The older the gas mask, the more likely this will be a problem.
That's all you need to know if you're just purchasing one for the STALKER aesthetic. However, if you're looking for legitimate protection against a gas attack, you need to do further research.
First of all, old military surplus filters won't be good enough. The chemicals in gas mask filters degrade over time. Whatever mask you purchase, make sure it's compatible with 40 millimeter NATO standard filters. Many people will tell you that you must buy a modern, brand new mask for $200+, but a surplus mask should do the job as long as it accepts 40mm filters. If you're trying to seriously prepare, stock up on new filters and keep them in sealed packages.
If you're going to wear your mask to a protest or riot where tear gas is a threat, remember that tear gas is actually a very fine particulate, and a regular filter won't perform well against it. Make sure you purchase a filter with a P-100 rating--the highest for filtering out particulate. You can also purchase P-100 rated prefilters that clip over the actual filter.
Also remember that a gas mask alone is not enough to survive a chemical attack. The point of a gas mask is just an emergency lifesaving device to allow you to escape the gas. Many chemical weapons can either blister the skin, or be absorbed through it. If you're intentionally or knowingly going to be exposed to a chemical threat, you need a full on chemical suit and the training to use it.