Allow me first to welcome you to this internet site.
This site is dedicated not only to your 2nd Amendment rights but the AR15 in particular. We are of the firm belief as a whole the more mature law abiding citizens who own AR15s the more secure both our nation is as well as our 2nd Amendment right to continue to own and use these fine rifles. We would like to help you make your selection in any way we can, however it becomes a little daunting of a task for the first time buyer who has little to no experience. Hopefully this post will help a little.
First let me say, the core membership here has an amazing amount of AR15 experience and knowledge. Better yet, there are very few AR15 elitist buy only this or you are making one major mistake types. This is a good thing and one you should take advantage of. Most of the guys here are both avid collectors and frequent shooters.
Why are you buying this rifle?
This is the first question anyone thinking of buying a AR should ask them self. What makes the AR such an attractive gun isn't really its military looking features but the fact that its the most versatile gun system on the market today. There are almost limitless configurations, options, and alterations. Even better, if you want to try something different then for minimal investment you can change it. There's so many variations is why there is an entire forum to the weapon system.
It follows that the better an idea of why you want the rifle, the better your initial investment will be. There are no wrong answers to gun ownership and the natural assumption that goes unsaid is self defense. That is a for granted on any firearm and configuration. There is however a big difference between just own one that will live in a safe, shot frequently, what range/distance you want to shoot, hunting, as close to military like as possible, LEO applications, home defense, etc. There's even basic considerations like is weight or size.
Though the team here has years of experience on multiple configurations, its very hard to try to pass on years of experience in one thread. The closer idea you have to what you want, the better advice you will get.
I encourage you to speak right up for there is no wrong reason. It is your right to own a fire arm and not anyone's to tell you it should be this color or size even less so than the automobile you drive.
I have yet to see anyone given a hard time on this forum for saying, "I'm buying this for an investment, collectors item, of just because I can." We know not everyone is going to become an avid shooter though we will caution you that if any gun will turn you into one, it is the AR15.
The following a list of general internet terms that will help you with your posting.
"A Safe Queen"
These are weapons that the owner typically becomes proficient with, then spends most of its time in a safe. There's all kinds of reasons guns become "Safe Queens" and that's the stuff entire topics are made of, however its not really that important in context to buying a first AR as to why but only that it will be. For example, a rifle that depends on batteries for its optics only has a different consideration than one that doesn't. etc. It is helpful information to those who are giving you advice.
This is a general term to describe a rifle that its primary application is shooting targets. Of course, any AR can be used in the field in very harsh conditions but the range rifle typically accuracy is more important, weight is not as important, it influences your barrel length, optics that are best, and extras such a bipods a popular option on range guns.
This is a primary application for hunting small game such as groundhogs, coyotes, etc. Actually its a general term for hunting rifle. It does give the posters a good idea of what would work best for you as far as options go.
A gun primarily used as a Plinker is generally thought of as a gun that high rate of fire is more important than accuracy, ranges are pretty close, and a lower cost weapon more desirable than a higher cost one. Like always all ARs can be used for Plinking. This is just a general internet gun site term.
"Tactical Rifle or Bling Gun"
These are terms used to describe guns that are typical shorter barrels, collapsible stocks, and capable of having a variety of attachment options. Its good to try to think of them as the movie or video game guns like "Call to Duty 4". Its also used to describe SWAT type weapons basically close quarters weapons.
This is just a general term to describe rifles intended to reach out farther than 300 meters. This will usually involve higher level optics and a longer barrels as well as special barrels and fore stocks.
This is a general term to describe a rifle using the best of manufacturing techniques. That doesn't always mean it will have the best name recognition. We have a saying on the internet, "We are not the military so do not have to settle for what they give us." In this category, you will see many brand names mentioned that are not all that common in the general public. Most people looking for the ultimate rifle will research and become familiar with both manufacturing techniques as well as testing procedures.
Of course any of these terms can be used in conjunction with any of the other terms like "Ultimate Sniper Rifle" etc.
Where to Start
Its always best to start by visiting our sponsors. Take time to look at not only complete rifles but options for varying rifles. This will give you a basic idea of what if available and cost as associated with it. We have a good mix here of both Industry and Aftermarket sponsors.
Basic Components of an AR
Because the AR is a system not just a gun, its basic components vary quite a bit from what people think of as a gun. Its good to have a basic understanding of this.
"The Lower Receiver"
This is technically the part of the gun that the government considers the gun and must be registered. This is the part that magazine fits in and houses the trigger assembly. A stripped lower is the just the part without trigger components or any other part of the gun. It is the starting point for assembling your own rifle.
This is the receiver with the trigger assembly as well as typically a shoulder stock. These terms switch by who's selling them so one should read what is included. The general items are trigger and stock.
This is typically the barrel and everything you need to just slap down on top of a complete lower to give you rifle. Unfortunately, this term definitely is supplier dependent. Many people advertise complete upper but leave out the bolt and charging handle. That's something to look for. It is a very good option since assembling the barrel to the Upper Receiver is considered the hardest part of assembling a rifle. Most people who assemble their ARs do a stripped lower but Complete Upper.
This is simply a term to describe all the plastic parts of the AR like stock, hand guard, and hand grip. There are many options, styles, and colors and very often the most frequently things changed on rifles.
The basic concept of a gun and how it performs is a matter of physics and those characteristics have not changed since the guns conception. Longer the barrel the more accurate it will be at distance is an example of basic gun characteristics. One of the biggest innovations in gun technology concerning barrels was the advent of the rifling which was shortly before the Napoleonic Wars. From that point the Musket became the Rifle named after the little grooves in the barrel that spins the bullet so it becomes more aerodynamic in flight increasing the guns effect accuracy at range. To give you an idea the combat effectiveness of a firearm in range tripled by the advent of rifling.
The AR15 is a rifle. The most common barrel lengths are 14.5" with permanent suppressor or muzzle brake to make it the legal 16" required by law, 16", 20", and 24". There are of course some other lengths that are out there but those are the most popular. The rifle can become even more accurate by matching the twist rate or grove type to the bullet weight being fired. The most common twist rates in an AR are 1:7, 1:8, 1:9, and 1:12 and like the lengths a few others. The basic rule of thumb is smaller the bullet the higher the twist and vice versa.
For the most part the same general principles of a barrel apply to the AR. Thinner the barrel the faster it will cool, thicker the barrel the less harmonics from vibration, longer it takes to get hot but longer it takes to cool, all barrels when hot due to metal expansion lose accuracy, and a warm barrel will be slightly more accurate than a cold one. The AR however is a little unique in that it has various barrel contours on many barrels to compromise some of these criteria.
Chrome lining, chamber, bore, or both is often a major topic. The M16 was first introduced with a non-chrome barrel just like most other rifles of the period. In the humid environment of Vietnam it was found corrosion could be an issue. Chrome was added as an upgrade to reduce this problem. Chrome also added to the life of the barrel as far as total number of rounds fired. Technically you give up just a tad of accuracy with chrome but it is very little and typically not a concern except for the long distance shooter.
For most of us, chrome or not is really not a major factor one way or the other. Our rifles will not see the same conditions as Vietnam or the military, however tt does have one major advantage in that it is far easier to clean.
The military rifle M16 is actually a 5.56mm cartridge a very slight variation of the civilian .223. The 5.56mm is a slightly larger cartridge and depending on the specific ammunition can have higher pressures and faster muzzle velocities. The AR can be chambered for either .223 or 5.56mm. A rule of thumb is firing .223 is perfectly OK in a 5.56mm since its smaller but not so desirable to do the opposite. Both ammunition types are readily available on the market. All military surplus ammunition will be 5.56mm and commercial can be either or.
Though this is discussed often, there aren't that many, if any, reports of catastrophic failures firing 5.56mm in .223 chambers. It does follow though if the 5.56 brass casing is ever so slightly larger it will have wear on the brass a consideration if reloading and wear on the chamber eventually over a large number of rounds.
Bling is simply an internet term for anything added to an AR other than what came in the box with the rifle. That includes optics, lights, lasers, night vision, extra hand grips, or special anything, etc.
There are many fine AR manufacturers on the market. Generally the vast majority of them make a fine rifle that will reliably send ammunition down range time and time again. Because there are so many variations or options, sites like these are very popular on the internet. Its often a good idea to think of the AR as just a like car in there are many styles, colors, options, specialties, quality differences, and brand preferences but for the most part they all work. A key feature of the AR is its Military Heritage which means one part from any rifle can be used in another. That kind of levels the playing field more so than say one car brand to the other. Its sites like this one that discuss those fine points.
I hope you find this post helpful and if anyone would like to ask a question or simply add to what I have posted, please feel free to.