This is intended to be a guide for the first time buyer of the semi-automatic AR-15.
The goal of this article is to allow you to get the most of what you desire for the least amount of money. We will go through the decisions one by one, highlighting the pros and cons, so that by the end of this guide, you have some opinion on what you're after. First things first
To Build or Not to Build
Many people build their own rifles from kits. This section will cover all recommendations when building your own rifle.
To start, a stripped lower receiver is needed. This is the milled out (or forged) aluminum heart of the AR-15. These can also be found as a carbon polymer that is lighter, but it will wear faster. Most people prefer a milled receiver that was born from a solid chunk of aluminum and they are also the most common. A mil-spec receiver means that the CNC machine that created it used dimensions, tolerances and finishes (hard anodizing) specified by the military. Most all lower receivers are mil-spec and unless you're shipping out with some black ops team, you won't need to consider much more. This is also the part of the AR-15 that is considered the firearm, meaning this is what holds the serial number. That means yes, you need a background check to legally purchase a finely milled paper weight from a dealer. We'll skip designer finishes, Colt versus Para vs. Armalite vs. LMT and whatever, plus all the other nonsense you can argue on a forum over. Mil-spec is mil-spec. For the most bang for your buck, the prestige argument is moot.
The next most important aspect of your lower receiver is the caliber stamping. This determines what the rifle is intended to fire and its also a small legal trap, easily avoided. Since the AR-15 is modular and can fire several different calibers from the same lower receiver, it could happen that a secondary offense would be firing a 9mm round out of a rifle marked .223. Notice I said "could" and "secondary". Personally, I have never heard of such a case. However, I could see the case of someone committing a minor crime with their AR (shooting where they're not supposed to), being a bit ill tempered about it and having the mis-matched caliber nonsense brought up as some bogus illegal weapon charge. Easy fix for the paranoid. Get a lower receiver marked Multi-mod or Multi-cal and it will say to authorities that your rifle is intended to fire .223 AND 50 bmg. and anything else that'll fit.
Putting a lower together from a rifle kit is relatively easy with the right guide. I have a two parts series under videos I got from youtube. A blow up parts list is handy too. My first one took me about an hour using none of the right tools or vises and no previous knowledge. The benefit: I know my rifle backwards and forwards and if something goes wrong, Ill know why and what to do to fix it myself.
The benefit of buying a complete rifle: Having a warranty and its someone else problem if something goes wrong out of the box. Second it was put together by a professional and there is less chance of damage to the lower or having a part missing than if you do it yourself.
Any rifle kit will come with everything need to turn your fancy paper weight into a precision rifle or carbine. All the lower receiver parts are included along with the butt stock, pistol grip and upper receiver (including barrel). Most all kits come with an upper receiver already assembled with the barrel, bolt/carrier group and hand guard. This is because a responsible company will assemble and test-fire the upper to make sure the head spacing is correct. This is the critical distance that assures that a live round is seated in the chamber correctly. Once the lower is built and the butt stock is installed (easy) the two receivers mate with a pair of take-down pins one in front and one in the rear. The rearward take down pin will be used regularly for cleaning and service. The front pin won't need to be removed unless you are changing uppers. Some small play or slop may be found between the two receivers. This is normal, although complete rifles are usually quality checked against it so the rattle is to a minimum. The hairline gap between the two receivers is necessary for proper function when the rifle heats up. The rattle can be solved with an accuwedge or any rubber whatever you can form fit into the lower.
There really is no clear cost vs. benefit here except what was stated about the lower receiver and its many small parts. The upper receiver in a kit is usually warranted against failure just like any new complete rifle. Be wary of cost when it comes to these kits.
I wouldn't usually throw a distributor under the bus, but Blackthorne products has had problems with finish quality and missing parts and I do feel the need to warn against buying a kit from them.
Many "elitist" arguments are made about mismatching uppers and lowers as if it were taboo or an insult to the AR gods somehow. Other than fit and finish, there is no reason for this to be a concern when it comes to performance if you've bought a decent rifle kit. Unless you're shooting long range competition where ALL tolerances need to be tighter then your rifle is a mismatched custom job anyway. Beyond that, its a personal preference. Purist have been known to seek out colt stamped magazines at a premium when a magpul is one of the best and cheapest magazines in the world.
Bottom line. Don't blow an extra $500.00 to $1,000.00 on your rifle just because someone on a forum said you had to. Do it because you're a fanatic and you genuinely love what you've bought or built. A great many soldiers coming back from overseas choose to build their own ARs from whatever quality parts they can find and they would be the first to tell you a name isn't everything. However, the benefits to buying a complete rifle usually include things like extra magazines, hard cases, cleaning kits and more complete warranties.
Getting what you need
This section covers some important necessities to consider.
Chamber (.223 cal vs. 5.56 mm)
Regardless of building your own AR from a kit, buying complete or buying it piece buy piece, chambering your AR-15 in 5.56mm is highly recommended. The .223 cal and the 5.56 mm are nearly identical in every way except the most important factor. The 5.56 mm is a "hotter" load, meaning its round has a higher velocity caused buy a higher compression of gasses at the chamber. This higher compression in a .223 chamber wont blow your face off but it can cause the head spacing to change and may lead to malfunctions after a few hundred or thousand rounds. The smart move is to chamber your new rifle with the highest tolerances to pressure. That way your 5.56mm rifle can fire both the .223 and the 5.56 with no worries.
The same is true for .308 cal vs 7.62 x 51mm if you're after an AR-10 or other .308 AR platform. In this case, the hot load is the .308 and it WILL cause damage to a 7.62 x 51mm chamber and head spacing. That mistake is well documented and has destroyed many surplus 7.62 rifles. So always make sure your 308 says ".308 cal" on it.
There are a few things that are the the most common upgrades and should be taken into serious consideration. They are, in order of importance:
1) Good sights. If you can't hit what you're aiming at, then you're just being loud. A good font/rear sight set or scope is always a good investment. You don't have to break the bank to do it either. Read the reviews and you'll be surprised what kind of set up you can get for cheap. Keep in mind that the steel front sights built into the gas block are just fine for most people and will out last many of the aftermarket sights that attach to a hand guard rail. Keep in mind that you can and will get what you pay for. Be wary and do your homework.
2) Good magazines. No excuses here. Magpul makes some of the best, highest rated magazines in the world today and they are currently in use by tens of thousands of soldiers in combat. They are also among the most affordable. No excuses.
3) M-4 feed ramps. This is part of the barrel extension that goes into the upper receiver. This type of feed ramp is an upgrade from previous designs and allows better, more reliable feeding of rounds into the chamber.
4) A hard chrome bolt or high quality phosphate finish bolt and carrier. ARs need cleaned and this just makes it that much easier to do it. They also slide better inside the receiver and resist carbon build up. As always, a well lubed rifle is a happy rifle. Keep her slippery.
5) A good charging handle. If fast is a factor then you want to spend a little extra to make sure you can clear jams or re-load quickly. Tactical charging handles have many different shapes and are easily found and upgraded.
6) The 22lr conversion. The AR-15 has a lot to offer in versatility and this is one of the best. It takes under 10 seconds to Change the bolt, change the mag and your'e plinkin at 5 cents a round. The CMMG stainless is an affordable and reliable upgrade. Ammo selection is important though. Soft point rounds may have trouble feeding. Experiment with different brands and you'll get it dialed in. Three words. TOO MUCH FUN.
Getting what you want
This section covers everything else, pro and cons, whether you are building your own or purchasing a complete rifle.
Barrrels (chrome moly vs. chrome lined)
This is another hot topic among AR enthusiasts that has more to do with how you are going to use and treat your rifle than whats right or wrong. Chrome-moly means the barrel is made of chromium molybdenum alloy steel and then rifled. A chrome lined barrel is just that, a lining that is then rifled and it is subject to imperfections that can limit accuracy. Chrome lined barrels are easier to clean and will put up with being left in a damp area for long periods of time. Competition shooters prefer stainless or chrome-moly barrels. However, it is widely accepted that chrome lined barrels last longer overall. All target AR barrels are stainless, usually 24 and heavy as hell. The 18 bull barrels on some designated marksmen rifles are chrome-moly. A chrome lined barrel is ideal if you don't plan on keeping up on cleaning your rifle. But, be warned that an AR isn't the ideal rifle to leave dirty anyways. It is a precision machine that needs regular care. Bottom line: If they made an M-4 profile barrel in stainless with a parkerized finish, that'd be the ticket....but damn expensive.
What goes on an AR-15 in terms of hand guards, butt stocks, grips etc.. is all personal. It really is the best way to express your creativity with a deadly weapon. The only real advice to offer is that the more you buy up front the better. It used to be that one could get a basic rifle and buy what they want when they found a cool grip or the stock they were looking for and it would be cheaper that buying everything in one shot. That's all backwards now. Most of the discounts come at the point of purchase, meaning its more cost effective to get what you want up front than try and buy it separately. The cost of shipping when buying parts online is the biggest factor here. This formula doesn't work with all cases and all products but it is something to keep it mind. Beyond that, some of the best and most cost effective gear comes from Magpul again. This is one of those things where serious window shopping is in order.
Single stage, two stage, adjustable. Its all about what kind of shooting you'll be doing. If you're in the marines, a single stage trigger (that comes in a rifle kit) is going to do fine. Its the competition shooters and squad snipers that go for the high dollar timney trigger and the like. Unlike the quad rails and pistol grips, there isn't much discount here buying this stuff up front. Its specialty and you should shoot some first and see if you really want it.
This is relatively new technology for the AR platform and old tech for the rest of the firearms world. One of the criticisms of the AR-15 is its direct impingement gas system that dumps hot gasses from the barrel into the receiver. The direct impingement system was designed to shave precious weight from the front of the rifle and center the balance towards the shooter. This made the M-16 a faster rifle and in its early versions, an unreliable one. Hot gasses dumped into the receiver result in carbon build up in an area critical to the function of any firearm. This also results in over heating under sustained full-auto fire. A gas piston solves this problem by adding a solid rod that pushes the bolt reward rather than having a direct blast of hot gasses do the same work. This addition comes at a cost of weight and dollars. Be aware that aftermarket drop in conversions may be attractive but may also be painful to tune in to feed your rifle correctly. If a gas-piston AR is what you want, then buy one (or the upper receiver) that was designed to be one. Only experienced gunsmiths should attempt a gas piston retro-fit. Bottom line: If you're going to take your AR out shooting every week and service it as you should, this technology isn't necessary. If you're going into combat, you might want this because you may not have time to service your rifle properly. In short, a semi-auto gas piston AR is kind of overkill. but it would be nice to clean after every other trip to the range in stead of every time.
Flash Hiders and Muzzle Brakes
The standard attachment at the end of most AR-15 barrels is the A2 flash hider. A flash hider works by dispersing gasses away from the muzzle so that combustion ceases. All flash hiders or flash suppressors can be identified by lengthwise slots that run parallel to the barrel. There are many types and the most popular one shave a closed bottom so dust isn't kicked up while shooting in the prone position. Effect on accuracy is negligible and sound is not increased. Most flash hiders are all effective in nearly 100% flash dispersion. A muzzle break is a completely different device as it speeds and re-directs gasses from the muzzle in such a direction to make repeated shots more manageable because the barrel will tend to stay more level. Trade offs are the increased noise from the muzzle and its possible to affect accuracy, depending on the round and type of muzzle break you are using. Research carefully if you are considering a muzzle break. The flash hider...go nuts.
A World of Options
There are more customization options for the AR-15 than any other weapons platform on earth. To even call them the iPod of the gun world is an understatement. "When I get asked what route should I go? " from a first time buyer my eyes kind of glaze over. I was asked that same question by a friend of mine that led me to start writing this article.
The AR-15 is probably the most American of all firearms in that its very design allows so much innovation that it has created a multi-billion dollar industry to support its customization. So, whatever you choose, whether its a colt, armalite, bushmaster etc. or a rifle kit that you assemble yourself, let it be an expression of your individual taste. Make it yours, and have fun doing it.
Below is a near complete list of calibers that the AR-15 platform will support (most on this list require custom gunsmithing)
.204 Ruger (complete upper available)
.222 Remington Magnum
.223 Remington (5.56x45mm) (complete upper available)
.223 Remington Ackley Improved
.300 Whisper (.300/221, .300 Fireball (complete upper available)),
.300 Blackout (complete upper available)
.338 lapua (complete upper, bolt action only available)
AR-15, with bolt modification
.223 WSSM (complete upper available)
.243 WSSM (complete upper available)
.25 WSSM (complete upper available)
5.45x39mm (.21 Genghis) (complete upper available)
6mm BR Remington
6.5mm Grendel (complete upper available)
6.8x43mm SPC (complete upper available)
.30 Herrett Rimless Tactical (6.8x43mm case trimmed to 41mm and necked up to .308; the 6.8mm version of the .300 Whisper)
.30AR Remington (complete upper available)
7.62x39mm (complete upper available, though known for feed issuesbe wary)
.35 Gremlin (necked up 6.5 Grendel to 358),
.358 WSSM (various names, but all are some form of a WSSM necked up to 35 caliber, some are shortened to make them big game legal in Indiana)
.458 SOCOM (complete upper available)
.450 bushmaster (complete upper available)
.50 Action Express
.50 Beowulf (complete upper available)
.410 (complete upper available)
50bmg (complete upper, bolt- action only available)
AR-15 using a simple blow back operation using complete upper replacement
.22 LR conversion (requires only new bolt and mag for the .223/5.56 chamber)
.22 LR (complete upper available)
9x19mm (complete upper available)
40S&W (complete upper available)
41 Action Express
10mm Auto (complete upper available)
45ACP (complete upper available)
45 Win Mag
FN 5.7 (complete upper available)
Tac-15 crossbow (complete upper available)