Introduction to the AR-15:
How the AR-15 Works:
What is Mil-Spec?
Most AR-15 rifles look the same, however in terms of engineering and precision craftsmanship their quality varies greatly. There are very few that actually meet all of the qualifications to be considered 100% “mil-spec”.
Government agencies test out a rifle system before trusting their agents’ lives to them. Most can take the abuse. Some can not.
Tiers of Quality:
Below is a list of most of the major players in the AR-15 manufacturing game. The “tier one” guns are made to “mil-spec” and are certified tough enough to be used by our nation’s armed forces. The second list is very high quality rifles, that while not necessarily meeting each and every part of the military specification, are still considered tough enough to be used by some of our nation’s finest law enforcement agencies and departments, as well as civilian contractors operating abroad. Any rifle from these manufacturers should serve you well in a defensive role. The last list is lesser quality manufacturers. You should avoid these and use your hard-earned money to invest in what the professionals use.
Tier One AR-15’s:
Tier Two AR-15’s:
Unknown or Junk:
- AR Star
- Olympic Arms
Ammo in the AR-15:
Difference Between .223 Remington and 5.56mm:
- .223 Remington: One of the most popular rifle cartridges among American shooters. Optimized for accuracy (varmint hunting). Can be used in 5.56mm barrels. While similar to NATO-standardized 5.56×45 ammo, .223 and 5.56 rounds are not identical, so be sure you’re shooting the appropriate caliber in your firearm.
- 5.56mm NATO: Optimized for reliability (military). Loaded at higher pressures than .223 ammo. Pressure too high for .223 Remington barrels.
- It is safe to shoot .223 Remington out of a 5.56mm barrel, but you shouldn’t shoot 5.56mm out of a .223 barrel.
Military Ammo Designations:
- M193: 5.56×45mm 55-grain ball cartridge.
- M196: 5.56×45mm 54-grain tracer cartridge, red cartridge tip.
- M885: 5.56×45mm 62-grain FN SS109 ball cartridge, green tip w/steel penetrator and a lead core.
- M856: 5.56×45mm 64-grain FN L110 tracer cartridge.
- M262: 5.56×45mm 77-grain Open-Tipped Match/Hollow-Point Boat-Tail cartridge. Mod 0 features Sierra Matchking bullet, while Mod 1 features either Nosler or Sierra bullet.
Steel Case Ammo in the AR-15:
The clerk in the sporting goods section of you local Wally World told you not to buy the less expensive Russian/Ukrainian manufactured, steel-case, bi-metal bullet ammunition because it is dirty and will wear out your guns. The guy working in a retail store doesn’t have any idea of what he is talking about. Or does he?
In the mid 1990s I purchased a 1000 round case of Wolf brand, Russian manufactured, steel case 9mm 115 grain FMJ ammo. It was lacquer coated so as to keep it water proof, protect it during long-term storage, and keep the steel cases from rusting. I bought it with the intention of shooting from my new gen 2.5 Glock 26. In those golden days of cheap ammunition I was known to blow through it pretty fast. My guns stayed hot. While my Glock would eat anything with a brass case, I couldn’t even make it through a single 50 round box without the lacquer melting off the cases and causing them to stick in the chamber and not eject. The only way to get the empty cases out was to lock the slide back and pop the stuck empty out with a cleaning rod inserted through the muzzle. I had to use a brass chamber brush and scrub and scrub to get the chamber clear of all of the lacquer build up so that the gun would function again. I then had 950 rounds of shitty ammo and didn’t know what to do with it. Eventually one of our other members and I ran all 950 rounds through a Class-3 H&K MP5. The sub-gun shot every round full-auto without a single hiccup. It was filthy afterwards. I didn’t have to clean it, but I’m sure that who ever had to scrub 950 rounds worth of lacquer was pissed!
Fast forward to present day: Only Russian made “Brown Bear” labeled ammunition still has a lacquer finish. You can usually only find it in 7.62x39mm and 5.45x39mm, both of which are Kalashnikov rounds. (AK’s don’t care what you shoot out of them and will eat most anything.) Wolf and Tula do not lacquer any more. I have fired thousands of round of the modern Wolf and Tula ammunition out of my ARs, AKs, and Glocks. It always functions in my guns and is perfect for target practice.
Below are some YouTube videos that I’ve collected on the subject of whether steel case ammunition will damage the extractor in your AR-15, and if the bi-metal bullets found in some of the Russian and Ukrainian ammunition will damage your barrel.
While these YouTube videos are insightful with just enough information to help you form your own opinion, I highly recommend that you check out:
These guys use four identical AR-15 rifles and fire 10,000 rounds of Federal brass case ammo, 10,000 rounds of Wolf steel case ammo, 10,000 of Tula steel case ammo, and 10,000 rounds of Brown Bear steel case ammo. Throughout the 10,000 rounds of each type of ammo they test for accuracy, velocity, throat erosion, and chamber pressure. Their results may further challenge your opinions.
Will Steel Case Ammo Damage Your AR-15 Extractor?
Will Bi-Metal Bullets Damage Your Barrel?:
How To Remove A Stuck Case From The Chamber Of Your AR-15:
5.56mm / .223 Caliber Barrel Twist Ratios:
1×7 – Manufactured originally to stabilize the heavier SS109/M855 ball and M865 tracer ammo. Good twist if all you are planning on shooting is 62 grain ammunition. This is the twist ratio of a mil-spec AR-15.
1×9 – Good all around twist ratio. Best suited for 52-69 grain ammunition, but either end of the envelope will be questionable. Good for shooting either 55 grain or 62 grain military ammunition. Seen on many commercial-grade AR-15 rifles.
1×14 – Originally used on the early M-16 / AR-15 rifles with 55 grain ball ammunition. Understabilizes heavier ammunition and will affect accuracy. Creates a tumbling effect upon bullet impact. IMHO, better to shoot straight with a good HP bullet as your chances to hit are better and damage will most likely be greater. If you have an older rifle with this twist, stick to 55 grain ammunition.
AR-15 Parts Diagram:
How to Fieldstrip the AR-15:
How to Clean and Lube the AR-15:
- Scrub chamber & locking lugs.
- Scrub bore from the chamber end.
- Strip bolt assembly from carrier.
- Make sure carrier key is tight.
- Clean gunk out of upper.
- Lube everything.
- Hose out lower with degreaser. Lube moving parts.
- **Check gas ring friction. Extend bolt from carrier and stand the assembly on its head. If the weight of the carrier causes the assembly to collapse, you need new rings.
- **Most important: Keep chamber and locking lugs clean.
Five Most Common AR Problems:
Insufficient extractor tension: Causes cases to be left in the chamber or dropped loose into the feedway where they get in the way of the next round.
Loose key on top of the bolt carrier: Should be torqued down to 50’ lbs. with Loctite.
Blown primers: Shooting 5.56 our of .223.
Headspace: Reloads break after two or three loads because of too much headspace. Too little headspace mimics the problem of too little gas which is short stroke.
Failure to eject: Usually caused by combination of small faults, such as brass filings building up under ejector due to sharp edges on soft cases.
Stay away from: any aluminum magazine without a manufacture’s stamp on the baseplate, any “used” G.I. magazines, and any polymer magazines other than Magpul brand.
Aluminum “G.I.” Magazines:
Aluminum magazines for AR/ M-16 rifles, when manufactured under heavy quality control, are very reliable. Their weakness, however, is that their thin and delicate bodies and feed-lips can be easily damage if dropped or landed on.
Aluminum AR magazines are made in either 20 or 30-round capacity. There are a few low-grade manufacturers that have made 40-round magazines throughout history. Avoid these. Traditionally as a general rule, the lower round capacity of a magazine, the more reliability you can expect. The 20-rounders were considered the most reliable, and for a little less reliability you could get 30-round magazines. With increases in manufacturing technology and experience the 30-round magazines can be expected to be just as reliable as the 20-round magazines. Still, avoid the cheap 40-round magazines.
The manufacturer’s logo will be stamped or engraved into the bottom of the floor-plate of the magazine (shown left). Avoid magazines that do not have any type of manufacturer’s mark on the floor-plate. There is no way of telling who made them or how reliable they are.
Stay away from unbelievable deals on used G.I. aluminum magazines at gun-shows and internet listings. In the military “used” translates to “abused”. There is a very good chance that the magazine lips may be bent out of spec, or the spring may be worn out. New quality magazines are now too plentiful and inexpensive for you to take the chance with acquiring junk.
D&H Brand Magazines:
D&H brand magazines are considered top-of-the-line. They are made on former Labelle tooling. They are OEM for several AR-15 manufacturers. They are considered top-of-the-line. More soon!
Brownell’s brand magazines are considered top-of-the-line. They are approved for military use.
Surefire Brand Magazines:
Surefire (the company that builds tier-one weapons lighting systems and weapon sound-suppression systems) recently started selling 60 and 100-round aluminum magazines. The idea is that you can keep shooting your way out of trouble, rather than get shot while reloading. This is a great idea, but the downside is that they hang a long way under the rifle which can restrict movement and the ability to shoot from prone or unorthodox positions. They are supposed to be ultra-reliable, but they are very expensive. It is too early (as of Q3-11) to tell if these are as good as advertised. Like any quality, super high-capacity magazine, you have to make a cost/benefit analysis on whether the additional firepower capability is worth the additional expense (you can buy 10 high-quality 30-round aluminum magazines and carry 300 rounds of ammunition for the same prices as carrying 60 rounds of ammunition in one Surefire magazine). Also, if the single magazine of 60 or 100 rounds of ammunition is damaged (dropped or shot), then you are out that many rounds of firepower. If the same damage occurs to a less expensive 30-rounder, dump the magazine, load a fresh one, and get back into the fight. A final note: the 60 and 100 round magazines are very long compared to a 20-round or 30-round magazine. They will hang out of the bottom of the rifle considerably farther than lesser capacity magazines. This will greatly hinder your ability to fire from the prone position.
Colt, H&K, and C-Products Brand Magazines:
How To Disassemble a “G.I.” Aluminum Magazine:
The AR-15/M-16 rifle system was originally designed to use magazines manufactured from lightweight, thin aluminum. It was problematic to design a polymer AR magazine thin enough to hold a high volume of rounds, fit into the rifle, and still maintaining strength, integrity, and heat resistance of the magazine body and feed-lips. The magazine would need to hold together under fully loaded spring pressure, and then not melt when fired from hot, automatic weapon. Eventually advances in polymer manufacturing technology allowed the creation of plastic magazines thin enough and strong enough to be used AR/M-16 weapon systems.
The first successfully applied design was the fiberglass Orlite 30-round magazines manufactured in Israel and employed by the Israeli Defense Force (IDF). The first generation of these magazines was designed for Colt brand M-16 rifles used by the IDF. The design had a raised over-insertion/stop ridge or lip around the magazine at the base of where it protrudes from the magazine well. This lip design was intended to keep dust and sand from infiltrating up around the magazine into the magazine well, and to control how deep the magazine seats into the well. Some AR’s made by other manufacturers have slightly deeper magazine wells, and as such, older Orlite magazines will not go in deep enough to feed rounds into the action. This is particularly true with older Bushmaster brand rifles. A later revision of the magazine had the ridge moved slightly down the magazine body so as to accommodate rifles other than Colt. You can check the version number or mold code on the side of the body to see if is an older or newer version. Magazines with mold codes greater than “0/20″ (see photo below) should work in most AR’s.
Manufactured by Master Molder, Thermold magazines were used by the Canadian military for a brief time, and the company like to brag about it. Eventually they were taken out of service and replaced with traditional aluminum magazines. They are fairly reliable, but the Canadian military discovered that the feed lips on the magazines were prone to melt when used in weapons on full-auto. As a civilian with a semi-automatic weapon, you will probably not ever get a Thermold hot enough to melt the magazines, but with other similarly priced polymer magazines on the market that are more heat tolerant, I would stray away from them and go with either high-quality traditional aluminum magazines, or Magpul Industries polymer P-Mags.
Magpul P-Mag Magazines:
Magpul Industries P-Mags are considered absolute tier-one equipment. They are manufactured in both 20-round and 30-round capacity versions, and come in black, olive drab, and tan. There is a version that sports a thin, clear window on the side so the operator can view how many rounds are left in the magazine. When you purchase them, verify that you are getting the “M revision” version. With this design update the part of the magazine that inserts into the weapon’s magazine well has been modified. There were issues with their fit and function when used in some non-AR rifles which are designed to accept NATO M-16 (AR) magazines. Unless you think that you will ever use the magazines in a non-AR style rifle you probably shouldn’t really worry about it. Fortunately, the “M” revision has been out a while and I haven’t seen anyone selling the pre “M” version for quite some time, so you probably will not have to worry about it. Magpul now has a “Gen-3″ version out. There are some a few ergonomic improvements, but functionally they should be the same as the “M” revision.
Super High-Capacity Drum Magazines:
MWG Snail Magazine:
This plastic 90-round magazine has been around since the days of Miami Vice. It is more of a novelty item than a piece of serious equipment. Its plastic is less than top quality. It has a marginal reputation for reliability. When loaded into the rifle it adds the combined weight of the magazine plus 90-rounds of ammunition way out to the left side of the rifle, thus creating an asymmetric balance and a decrease to the rifle’s handling characteristics. They suck.
Below we can see Miami Vice’s Crocket and Tubbs about to blast a fool who was dumb enough to invest his hard-earned money on a MGW snail mag.
Beta Drum Magazine:
C-Mag “Beta” Magazine is a 100-round dual drum magazine designed to provide the operator with sustained firepower. It was used extensively in the early years of the post 9/11 war on terror by our military and private contractors. While exponentially higher quality than the MWG snail magazine, they are complex mechanisms, require careful maintenance and graphite lubrication, and over time have proven prone to malfunction or breakage during the stress and abuse of combat. Serious operators have begun to stray away from these. Beta magazines are also very expensive. For the Beta’s retail price of around $225 you could instead purchase more than 20 30-round high quality aluminum G.I. style magazines, and have the capability to load six times as much ammunition as the Beta.
There is absolutely no reason to spend the money on a rail system that free-floats the barrel on a short barrel M-4. You will spend a lot of money and not see noticeable improvement in accuracy. However if you are a serious shooter and see yourself varmint hunting or precision target shooting at long-range with a full-length AR-15, then it may be worth the money.
If you are on a budget there is no reason to go spend over $100 on a dedicated rail forend system. You can spend much less and add a single light-weight rail to the bottom of the forend. Lights can be easily attached and removed.
If you decide to change the stock of your rifle it will be very important to know if you have a Mil-Spec version or a commercial version rifle. Below is the difference.
AR-15 Optics Choices:
For detailed information go to Savannah Arsenal’s Rifle Accessory Page.
Stay away from UTG brand products, and N-C Star brand optics and accessories.
Backup Iron Sight (BUIS):
Why A BUIS?
To Co-Witness or Not:
What Are Good Brands?
BUIS on Bushmaster Brand Rifles With Removable Carry Handle:
Colt A3 Removable Carry Handle Sights are taller than A1& A2 Rear Sights, and require an .040” taller Front Sight Post.
What Distance to Zero Your Red Dot Sights and Backup Iron Sights:
It is important to zero the elevation of the sights with a single setting that will take the most advantage of the flat shooting trajectory of the 5.56mm/.223 caliber rifle round. The following diagram compares the trajectories of bullets when zeroed at 25, 50, and 100 yards. It is easy to see why the 50 yard zero is the best choice, and how your point-of-impact will never be more than +/- 2.5 inches from your point-of-aim, from close up and personal “bad breath” distance, all the way out to a distance 225 yards.
Battlesight Zero For Red-Dot Optics:
Simply zero your rifle for point of sight / point of impact at 50 yards. Make adjustments until bullet impact is right on the red dot. For shots at 300 meters simply hold over approximately one dot.
Battlesight Zero For BUIS Without Elevation Adjustment:
With the majority of BUIS you can not adjust the elevation of the rear sight. If you have a red-dot optic installed, first sight in the optic as precisely as you can at 50 yards. Then use a front sight post adjustment tool to raise or lower the front sight until the it appears that when you are looking through the front and rear BUIS and the optic that the red dot is horizontally intersected by the tip of the front sight post. If you do not have an optic installed, simply adjust your point of impact by adjusting the front sight for point of sight / point of impact at 50 yards.
Improved Battlesight Zero For Carry Handles With Adjustable Rear Sights:
The standard A2 rear sights on an AR-15/M16A2 were designed with elevation settings for 300 to 800 meters. The Santose Improved Battlesight Zero allows for an elevation setting of 50 yards / 200 meters for one of the most all-around useful trajectories obtainable with the 5.56mm/223 Remington cartridge when fired from an AR-15. Neither of the above sighting schemes allow for an elevation setting giving you point of aim equals point of impact at 100 yards. Since 100 yard shooting ranges are some of the most commonly found ranges in the United States, it would be useful to have such a setting on our AR-15s. This can be achieved quite easily with nothing more than a 1/16” allen wrench. It’s really just a matter of taking the Improved Battlesight Zero one step further. See this link to learn how to do this: AR15.com’s Revised Improved Battlesight Zero
.22LR Conversion Kits:
Using either a dedicated .22LR upper receiver or a .22LR conversion kit is a great way to teach a new AR shooter the fundamentals of shooting the rifle without the intimidating loud noise of the full size battle ammunition , and for the experienced shooter to maintain proficiency at a fraction of the cost of shooting full size .223/5.56 ammunition.
To shoot .22LR ammunition out of an AR platform, you basically have two options. You can buy a dedicated upper receiver/barrel set, or buy a .22LR conversion kit that simply replaces your bolt carrier and fires the .22LR bullets through your AR barrel. The dedicated upper’s barrel will usually be a 1 in 12″ twist (as opposed to your AR’s 1 in 7″ or 1 in 9″ twist). The 1 in 12″ twist will result in a better stabilized .22LR bullet in flight which may result in slightly better accuracy. .22LR rounds fired from a conversion kit and through your AR’s barrel may or may not be as accurate as those fired out of a dedicated upper, but I been very satisfied with the results using the simple and less expensive conversion kit. I can easily hit coke cans at 50 yards, and a full size paper plate at 100 yards. This is good enough for training purposes.
I live and swear by my CMMG brand .22LR conversion kit. When properly maintained, it is both reliable and accurate. They are around $160 and usually come with a 25 round magazine.
I originally only used Remington Golden Bullets and have always had really good luck and reliability. It is very interesting to note that after recommending the CMMG adaptor and Remington combination to two friends, they both reported disappointing reliability with it. After a little internet research I discovered that some CMMG’s will not reliably cycle Remington ammo and actually prefer Federal’s Bulk Pack .22’s. Both friends tried Federal’s Bulk Pack ammo and had great results. I tried the Federal ammunition and won’t go back to the Remington unless there isn’t any Federal to be had. Where as the Remington worked 85-95% of the time in my conversion kit, the Federal’s are closer to 99% reliability when used in a properly cleaned and maintained rifle. There is no rhyme or reason why one kit prefers one brand of ammo, and another one just like it prefers another brand, but this is not uncommon with .22LR caliber firearms. Two identical guns may have completely different accuracy and reliability results with different ammunition. I recommend that if you buy a conversion kit, buy a couple of hundred rounds of each brand of ammo and experiment to see which works best with yours.
Some people may worry that the lead bullets will dirty up the barrel and foul the gas system of the AR. The higher quality copper-washed Remington and Federal ammunition are not terribly hard to clean up after, and simply firing a round or two of full caliber .223/5.56 ammunition through the rifle at the end of your target practice with blow out any of gas system fouling that might occur.
I have an Eotech optic on my AR. I have it set up for a 50 yard zero (reason discussed above in “What To Zero the Back Up Iron Sight and Red Dot Optic”). I have experiment to see how much holdover I need to shoot accurately at 25, 50, and 100 yards. The results are shown above in “Eotech Cheats”.
AR-15 / M-4 / M-16 Operating Manuals in PDF:
- Buy a quality AR-15 / M-4 appropriate for your perceived needs.
- Purchase at least 10 quality aluminum or polymer 30-round magazines.
- Equip the rifle with an Eotech or Aimpoint red-dot optic (magnified optics if you live in a rural area).
- Install a quality backup iron sight.
- Zero optics and iron sights at 50 yards.
- Equip the rifle with a quality lighting system.
- Keep the weapon cleaned and properly lubricated.
- Make sure that optics and other accessories are properly installed with Loctite.
- Keep spare batteries for optics and lights.
- Practice, Practice, Practice.