"The best we can hope for concerning the people at large is that they be properly armed." (Alexander Hamilton, The Federalist Papers at 184-8)
"The supposed quietude of a good mans allures the ruffian; while on the other hand, arms like laws discourage and keep the invader and the plunderer in awe, and preserve order in the world as well as property. The same balance would be preserved were all the world destitute of arms, for all would be alike; but since some will not, others dare not lay them aside...Horrid mischief would ensue were one half the world deprived of the use of them..." (Thomas Paine, I Writings of Thomas Paine at 56 [1894])

        Bullets, the great equalizer, especially when coupled with the appropriate firearms, are the keystone to security and liberty of all people.
In the “Prepper” movement the reasons for preparations are many and varied. The biggest reason I see is that if some natural calamity were to render government impotent there is reason for every man and woman to keep and bear arms.
Situations that would render the rulers and enforcers impotent include, war, famine, nuclear attack, Electromagnetic pulse (EMP) attack, natural EMP incident from solar radiation, invasion of our country from subversive forces (internal or external), and well just any old thing that might cause mayhem such as economic collapse or loss of fuel/infrastructure. If you want to read two relatively decent novels written about such happenstances, then read James Wesley Rawles’ book “Patriots, Surviving the Coming Collapse” or William R. Fortschen’s book “One Second After”. I found both to be thought provoking and possible. Probability of either situation lies in another realm.  
Anything that changes the status quo of our little nest here in the USA could send troops into widespread oppression of folks and or desertion where the militaries and constabularies would abandon their posts to go home and take care of family and friends. All things considered a period of anarchy might ensue.
Now the way I see things is that if there is no regular law enforcement, things could get a little bit stupid. Hell, things could get real stupid. Dogs and cats roaming the world in marauding bands, stripping the countryside of all that it has to offer in the form of food or handouts. Well, should that become the case then I can guarantee you that there will be marauding bands of far more ruthless creatures known as human beings. We are creatures driven to survive at whatever cost, and there are those who have less than decent morals and scruples and would have the need deterring.
Now you can deter a knife attack with a club, you can deter a club attack with a sling shot, and a slingshot attack with a bow and arrow. But the only way to deter a person with a gun is either with another gun or a small nuclear device. Seeing as small nuclear devices are reserved for the exclusive use of government forces then I would recommend a firearm to protect you and yours in a time of mayhem.
There are those folks on the prepper shows who say that firearms just do not fit who they “are”. Folks with this attitude probably won’t make it far if we find ourselves in an age of chaos. Those folks will find themselves rapidly consumed by any ruthless group moving through their area.
Remember, in the realm of firearms you will pretty much get what you pay for. Considerations in firearm selection would include, experience of the person, size of the person wielding the weapon, availability of ammunition, type of terrain you live in, and any other thing you can conjure that may have an impact on your survival. Always remember, if things go south and you find yourself defending what is yours that the situation will include a two way shooting range. Yes, the opposition will probably shoot back.
Looking at recent legislation here in Colorado, the state legislature failed to pass a law that prohibited law enforcement from confiscating firearms from folks in the case of natural or manmade disaster. So what the state legislature is saying is that you have no right to defend yourself with a firearm in the case of some unforeseen calamity. I might recommend learning how to properly cache a weapon and ammunition if you have a feeling that the good guys might go bad and try and take your weapons. If that happens and you have weapons and ammunition hidden then it makes it difficult for others to take what “they” can’t find.
However, the constitution and your own personal liberty and force of will guarantee you the right to protect yourself.  Now if I were gonna get a firearm for TEOTWAWKI, I would get myself informed about what types of firearms are out there.
There are big guns, little guns, and in between guns. There are long range rifles such as .50 caliber Barrett and .338 Lapua are two of the most popular, but for many folks these may be cost prohibitive. Long range guns can reach out and touch someone between 100 and 2000 yards. The nice thing about long range guns is that the further out you can engage a bad person, the less of a threat the bad person will be to you and your stuff. But how do you determine if at 2000 yards if someone or thing is a threat to you? Really good glass (binoculars, spotting scope, or mil dot scope) and your own analysis are about all you can go by.
There are medium range guns, anything with a range out to about 1000 yards, these include pretty much anything in the .30 caliber realm such as .30-06, .308, or some other war calibers such as 8mm Mauser, or 7.62x54R (most Russian Weapons through WWII). Think knock down.
Then there are the closer range rifles such as AR-15s. AR-15s are very popular, though effectiveness is another story. Light weight rifle, light weight ammo and light weight accoutrements such as magazines and cleaning equipment make these attractive for defense of the old homestead. With a maximum effective range of about 400 yards (by an effective marksman) these weapons are a fairly decent deterrent to would be marauders. Coupled with a high rate of fire these weapons are pretty much just that, a deterrent. Other popular closer range rifles include SKS and AK-47 variants in 7.62x39, and the AK-74 variants in 5.45x39.
Pistols and shotguns are the best close range defensive weapons you can get. For anyone not well versed in weapons or semi automatic pistol use I might recommend wheel guns (revolvers). Revolvers are a very good idea because revolvers seldom, if ever, jam. I think anything below a .357 pistol is, well, just not worth the money. You might get lucky and again you might not. But with a .357 you have some real knock down power, but you can practice with .38 Special which is much cheaper ammunition. In the shotgun arena 12 gauge pump is the way to go. One of my favorites is the Remington 870. One of the most tested, true, and affordable shotguns out there. For defensive purposes, never less than number four shot. Remember, the smaller the number in shotgun ammo, the larger the pellets. 00 Buck (called double ott buck) is very a very good choice for external defense. Inside the house seven shot because the shot will usually not penetrate two layers of sheet rock.
I recommend a decent .22 Long Rifle or .22 magnum rifle for small game. The ammunition is cheap and plentiful and can still get the job done in a pinch.
There are a lot of considerations when you go gun shopping. To get in the know, talk to a friend who is well versed in firearms use, review articles on the internet and in gun magazines. Then, take a class if you have little or no experience with firearms. Remember, if you act stupid with a gun, it will hurt you.  
In any case, you will get what you pay for, usually.  Research, education, and experience are the only things that can make you effective with a firearm.
Next week I will take a break, this dog needs a rest. However the following week we will take a look at the band-aid aspect of TEOTWAWKI medical considerations. WOOF, I need a vet!
Really Scary Thoughts……
        ….I went boar hunting in Bosnia. I searched Bosnia from one end to the other and found one set of boar tracks. That was in 2004, 10 years after the war ended. Before the war there were thousands of wild boars in Bosnia. (Former US Army Soldier stationed in Bosnia).
        I was a state prison guard at a prison in Arizona. If the government were to collapse, our orders were to execute every prisoner from minimum through maximum security regardless of their offense. (Former Arizona State Prison Guard)