Going one step down to 1/8 brings the stability factor to .9, which is the realm of “unstable.” Without the odd ballistic characteristics of the M856 due to its long length, but relatively light weight for size due to the hollow… Read more ». This does bring the length back up to the legal 16.1″, but it also makes it difficult to do any future modifications. I want you to understand that the ultra-specialized configurations only make a significant difference when in the hands of highly practiced shooters. These grooves “grab” the bullet and impart rotation. This has a skinny profile near the receiver and a thicker profile towards the muzzle. Don’t spend an excessive amount of money chasing accuracy. With the pencil barrels and me as the shooter, 2 MOA is plenty good. A manufacturer may claim their barrel is 4150 steel, but that doesn’t mean it’s actually certified under MIL-B-11595E. The velocity required to punch a hole in a piece of paper or ring a steel plate is one thing. That is wrong, don’t believe it. How did Faxon come up with such a lightweight barrel? I’ve written a much longer article about this nitrided barrels, so this is just a snapshot. Selecting the right barrel for you is a confusing process when you don’t know your needs. These barrels deliver tight groups and consistent performance all day, so long as you don’t abuse them. CHF barrels are, in theory, tougher than barrels made with button or cut rifling, but I sincerely think that it only matters if you’re looking for bragging rights. Barrel ID honed after finish per USGI TDP. There are other chambers that split the difference between the two, like .223 Wylde or Noveske’s Match Mod 0. cheers!! To ensure you have the best experience possible, this website uses cookies. In the real world, the difference is so minuscule that you’re never going to notice it and it’s not something I would consider as part of my buying decision. Small Misc Parts: Battle Arms Titanium Gas Block .48 $80. just assembled a 16" Faxon Gunner profile/ALG blem HG this afternoon,haven't installed the sights yet. Buy Faxon 18" Pencil Profile AR10 Barrel, 308 Win, Nitrided: GunBroker is the largest seller of AR15 Parts Gun Parts All: 886795648 Each Faxon Firearms 5.56 NATO Nitrided Pencil Rifle Barrel is button-rifled, creating a more precise barrel design with consistent bore and groove dimensions. Combined, the soldier could carry much more ammunition and participate in firefights for a longer period of time. Great article! Traditional rifling consists of grooves cut down the length of the bore with edges that “grab” the bullet. So when I offer my suggestions, realize that these are the companies that I know, like, and trust– but that doesn’t mean they’re the only game in town. Machined of steel, phosphate finish, for .625 barrels. It does not say what caliber it is anywhere on it. Of course, this varies from manufacturer to manufacturer. For more information, check out privacy page. very helpful info!! Muzzle Thread: 1/2-28 TPI... Can be used in place of a peel washer to mount compensator/flashiders. The fact that they were standard M16A2 and A4 barrels and did not meet the accuracy requirement for a light sniper rifle didn’t matter. Very helpful. This is most people, including military members who live with their rifles. Criterion uses this in their “Hybrid Profile” barrel I suggested at the start of the article. The stability factor is a combination of the spin rate and the shape of the bullet. Hey Matt, thanks for commenting! If you need assistance selecting the best AR Barrel for your custom AR build read this article. I’m flattered, Shane, thanks for the comment. To improve corrosion resistance and wear characteristics of combat rifles, it’s important to line the bore and chamber of a CM barrel with chrome. This "Pencil" profile Chrome lined barrel is the same size and finish as the original AR-15, XM16E1, M16 and M16A1 models. Here’s some numbers to illustrate what I’m talking about. My favorite barrel in this class is Criterion’s Hybrid Profile. Rifle: 15 1/8" We'd love to hear your thoughts, leave a comment. Increased velocity means that the bullet drops less at for given distance than a bullet that started off slower. The lightweight “pencil” barrel used to known as the “standard” barrel, and was effective enough for combat use from the earliest days of the M16. This is a true statement. Mid: 11 7/8" Notice how the overall extreme spread of impacts shrinks as the barrel length increases. AR-15, M16, M4, 11.5",BCM Enhance Profile Barrels. For rifle barrels, this expansion negatively affects the accuracy of a barrel. The balance here is how the barrel handles heat versus how easy it is to maneuver. But I am saying that there is a reason for the price difference. 410 is harder and more durable, owing to its lower sulfur content. I want to leave you with one more piece of advice. You could also buy a complete upper to put on your SBR’d lower and then have both configurations… Read more ». The same applies to 4140 steels. It then moves into the bolt carrier, where the pressure pushes against the back of the bolt and the rear of the carrier. Heavy barrels are slower to heat, so they retain their accuracy longer, but also slower to cool down. Cut rifling is the original “old school” way. To line a barrel, manufacturers remove a thin layer of steel from the bore and replace it with chrome. If anything, longer barrels reduce accuracy potential. Carbine gas for longevity and reliability. Even BCM’s Enhanced Lightweight Fluted barrel is 2.5oz heavier than the Faxon counterpart. I’ll call them Wildcard Arms. Quick view Out of stock. A battlesight zero, sometimes annotated as “BZO,” means picking a zero distances that keeps all of your shots within +/- some distance of the point of aim. For your next short-barrel rifle build, browse our choices of 7.5” – 14.5” short, SBR and Pistol length barrels. The .223 and 5.56 are very closely related. Thank you for taking the time to write this. It doesn’t do anything particularly better than other options, but it has good all-around performance. I used this particular barrel on my Minuteman KISS Rifle (pictured). I put “budget” in quotes because, obviously, it’s still more expensive than the lower end of the market. The 16″ length is the most common AR-15 barrel length sold today. Wow , Thank you Sir well written for this novice and extremely informative. The gas required to do this bleeds out of a small hole in the barrel. You can still develop a huge amount of skill on 1,200 rounds per year of structured practice. It’s just that pressure at exit is higher because that exit is closer to explosion in the chamber. That is more accurate than the average shooter is capable of, especially when most users are blasting cheap ammo that isn’t capable of better than 3-5 MOA to begin with. Add to Cart ; 18” 6MM ARC SPR Rifle Length W/15” Atlas R-One M-LOK Handguard Complete Upper $594.00. The trouble is that companies throw a lot of marketing dollars around to convince you that you need the latest and greatest or you’re going to lose the match, be uncool, or even wind up dead in the street! Thank you for a very thorough, well-researched, and pragmatic page on AR-15 barrels. This is where the real differences between chrome moly (CM) and stainless barrels become apparent. Being both 4150 and 11595E certified is more difficult, and thus more expensive. So, what size buffer And buffer spring will work Best? This case is about 60-65 Rockwell, as opposed to 28-32 found on normal barrel steel. Eliminates the Weak Link in Direct Impingement Gas Systems Very helpful for my first AR-15 build! Muzzle Thread:... 4150 QPQ coated inside and out for amazing corrosion resistance and durability. One Security Forces Airman put it to me this way: the 20″ barrel is easier to shoot, but harder to live with. If you’re a little more budget conscious, check out the Rainier Arms Mountain Series mid-weight contours. If anything, polygonal rifling is slightly easier to clean up due to the smoother surfaces, but you, aren’t likely to see any real difference in accuracy. looking to build a more tactical for the wife (and myself lol). What barrel length would you recommend? I will build another 18 inch but I am worried about my lack of knowledge regarding the 18 inch barrel and gas systems; whether to use a mid length or rifle length and the proper gas port. This jig will aid you in drilling out the barrel & gas block for a taper pin. Due to the tolerance variations in the M&P Slide, the barrel is semi drop-in. If you live where it gets below freezing, stick to 416r stainless. Barrels in stock and ready to ship! Look at the velocity chart above and how peak velocity occurs at the 20″ length. This site uses Akismet to reduce spam. The new CMMG  224 Valkyrie barrel is engineered to deliver on this exciting new caliber’s promise of long-range accuracy and high-energy performance. If you are buying a hammer-forged barrel, it probably came from one of these plants. Some people speculate that you can over-stabilize a bullet if you fire it through a barrel with too fast a twist rate. Awesome article! Button rifling is the military specification and involves forcing an extremely hard “plug” through a smooth “blank.” This cutting plug creates the grooves as it passes through the bore. As the bullet “uncorks,” the pressure in the system equalizes back to “neutral” atmospheric. As part of that, I put together these two charts. If you’re sticking to a budget, then the Faxon Gunner Profile is a great option. Now that we’ve covered AR-15 barrel length, let’s talk about profiles. This comes at a price, though. When you think about it, the difference between 150-ish meters and 200-ish meters effective range isn’t a big deal if most of your shooting is inside 100 meters anyway. One of the original engineers who designed the process founded the company. Let’s take a fictional gun company getting their start. The first chart compares a 100-yard zero for a 20″, 16″, and 12.5″ barrel. BCM Low Profile Gas Block for AR15, M16, M4, M4A1. Also, as a bonus, we civilians can take advantage of configurations the military never fully adopted. Faxon started out in the aerospace manufacturing business so they know their stuff. BCM® Standard 14.5" Mid Length (LIGHT WEIGHT) Barrel, Stripped. Barrel Gas System: Rifle This is the most common alloy you’ll come across. For those who want absolutes, pinning a low profile gas block will insure your piece of mind. The concept finally rose to prominence when the GWOT started ramping up in the early 2000s. great post. They measured the bore pressure at bullet exit after cutting the barrel down one inch at a time. Unless the company doing the nitriding is very careful, there is a risk of undoing the important stress relief work. The bottom line is that chrome lining does not deserve the negative accuracy reputation it has today- so long as it comes from a quality manufacturer. They aren’t doing much to accelerate the bullet at that point. (In fact, I think that particular vendor uses the same photos for the fluted barrel upper as they do for the standard barrel upper. If this is the path you’re going, then you’re probably building out a Recce Rifle or a Designated Marksman rifle. This site and its community are a labor of love. I hope you found this guide useful. Generally, these are the most expensive barrels due to the extra time and quality controls required. Traditional adjustable AR gas blocks often require tools to adjust the settings. I’m a marine and my issued weapon is the h and k m27. The 18″ barrel length has an interesting story, and it’s well documented by the Small Arms Defense Journal. That configuration will serve 90% of shooters well for a long time. These inconsistencies disturbed the bullet and reduced accuracy. Hi, sorry, didn’t see your response for awhile. Shorter barrels, in contrast, are easier to handle but come at the cost of higher operating pressures, increased noise, and accelerated wear on internal parts. CMC’s propriety In house machining, production and Quality control inspection process's allow us to attain an ultra-precise barrel with enhanced slide fit & lock up for improved accuracy. This article summarizes just about everything I’ve learned about AR-15 barrels in particular, but the lessons apply just as much to rifle barrels in general. or both. In other words, the rifle and sights are steadier in your hands. Barrel Length: 20" Marty, you are correct. If they don’t, then you may be getting a barrel made with plain AISI 4150 steel, which has looser tolerances on its chemical composition. Mrgunsngear did a short test with one of your 16" pencil barrels where the group seemed to open up from about .75 to 1.25" at 100 yards after a 30 round mag dump, I would love to see more tests like this. There is a charge, combustion chamber, projectile, and length of hollow metal tubing. The barrel affects accuracy, reliability, and handling of your weapon more than any other component. Learned much. I think that should count for something. You can read more about that in my article on weight and balance. Here's my BCM 14.5 carbine. This specification is MIL-B-11595E, and lists out the chemical composition required to be compliant. But with the popularity of 77gr SMK for match shooting, 1/7 twists now reign supreme. The Strike Industries Enhanced Steel Gas block combines form and function to bring you a cost effective, robust, but lightweight gas block. There isn’t much difference in performance between them. I’m not saying that Athena’s barrels are junk. When you think about it, the difference between 150-ish meters and 200-ish meters effective range isn’t a big deal if most of your shooting is inside 100 meters anyway. In contrast, a thick profile from end to end, the “HBAR” profile, makes a heavy rifle that sustains accuracy over a long string of shots. Nitriding is a surface conversion process whereby manufacturers submerge the barrel in a nitrogen-sodium solution and heat to a high temperature, usually between 750 and 1200 degrees. I understand I may have some AGB and buffer tweaking to do if I do the barrel… Read more », Hi Brian, thanks for reading. This difference in pressure affects the noise, concussion, flash, bolt carrier velocity, and long-term durability of the weapon. Barrel Profile: Big Gunner 4140 includes about .40%  carbon, and 4150 includes about .50% carbon– hence the 4140 and 4150. Home » Equipment » The AR-15 Barrel Cheat Sheet: Everything You Need to Know. IMPORTANT: Do not confuse 416r with regular 416, they are not the same. 416r is an alloy formulated by Crucible Industries specifically for gun barrels. It has more sulfur than 410, so there’s a slightly increased probability of sulfide stringers under fatigue. We have factory direct pricing on everything you need for your AR-15, AR-10, and AR-9 including complete upper assemblies, lower assemblies, barrels, BCGs, bolts, and we also manufacture Glock and 1911 barrels. The Navy signed on and dubbed it the Mk12 program. The choices we have to make to affect these traits include: There is no getting around it. The nice thing is that this over/under is fairly predicable using external ballistics. That’s a fancy way of saying that the barrel could suffer catastrophic failure under fatigue. Heavy barrels are suited to rifles that need to maintain higher levels of accuracy over long strings of shots. Beyond that, I know and trust LMT’s options. The smaller the number on the right, the faster the twist rate. If you do enough shopping around you’ll eventually come across a manufacturer touting their various special polygonal rifling patterns. V Seven Light Ejector Port Door .29 $37. The M4s with the carbine gas systems, on the other hand, were breaking bolts pretty regularly as they approached round counts around 10,000. I especially appreciate the complete absence of the usual political slights and sarcastic undertones found on pretty much EVERY gun-related site or forum. .625" Gas Block Dia. The Navy had trouble requisitioning 20″ match barrels because “the system” kept telling them that 20″ barrels were already in the supply chain. I’ve found it to be much easier to clean and I like the operation better than the m4 I was originally issued. If you’re past the first AR-15 and want to dive into the world of customization, or even building your own, then this article is for you. It is not an ideal solution for barrels that see very high volumes of sustained rapid fire. I do intentionally avoid political drama for a lot of reasons- and a lot of that is because of what you stated, it’s easy to get anywhere else. The man who trains with a stick will defeat the man who plays with a sword. If you see a barrel advertised as 416 stainless, ask if it is actually 416r before you buy it. They do heat up quicker but nothing to worry about since the A1 used the same pencil barrel. I’m sure you’ve see a lot of folks talk as if longer barrels are more accurate and use that as a reason to justify them. That is right around the upper range of the nitriding process. This can make it a little touchy about ammo selection in cold weather. But because each barrel is made to a high spec and consistency, Wildcard gets to charge a premium price for the product. Does adding a suppressor effectively change the barrel length increasing the projectile velocity. The 18″ rifle-gassed barrel is pretty well figured out at this point. Give yourself room to experiment without tripping over federal law. There are configurations like the M16A5 which help with the maneuverability aspect, but a shorter rifle is always easier in cramped quarters. The actual effect of the whip is very small and not something you should be concerned with until you are a seasoned match shooter. A BCM extractor kit solved that. But 5.56 chambers work safely with a wider variety of ammunition. Most of us will never shoot that much. But, despite all the text above, the difference from one configuration to the next is not as important as the quality of the manufacturer. Thanks Matt! Manufacturers insert a tungsten “negative” mandrel into a smooth “blank.” A large machine hammers the blank around the mandrel until the desired rifling pattern forms. But 4 inches of suppressor doesn’t offer the same boost as 4 inches of additional barrel length. So we can leverage this behavior to our advantage. They also come with increased pressures, loud noise, and reduced velocity. BCM Bolt Assembly 1.25 $80. Available in 223 Wylde, 1-8 Twist. We measure how stable a bullet is by applying a gyroscopic stability factor. I’m simply illustrating how much practice shooters at the highest levels are actually putting in to be were they are. I have learned a lot from your post. When I was in the military, a base armorer once told me that he practically never sees broken bolts from the M16A2s they had on the racks.