This is a follow-up to the post What is “milspec?”

AR15s (and their accessories) generally fall into one of four categories:

1. consumer grade
2. duty grade
3. sporting
4. boutique

Consumer grade ARs are those intended for the hobbyist. They might be geared towards hunting, casual competitive shooting and home defense; but mostly they’re intended, and only appropriate for, target shooting at the range. Not all of them are cheap, but affordability is usually the biggest selling point in this market. You might, however, pay for brand or cosmetics or even features like lightweight components. Drivers in this market are low price, features over substantive quality and brand recognition.

Duty grade ARs are made for military, law enforcement and serious shooters. They’re driven by consistent quality and reliability because they’re used in applications where failure is going to come at a high cost.

Sporting ARs are those made for hunting, bench rest, competitive shooting, etc. While the quality may be high, at least where its applicable to their intended use, function is often sacrificed for weight savings and recoil mitigation, and low end parts of unknown origin are often used. For example, let’s say I were making 24″ bench guns; my concern for the bolts would be mostly for dimensional accuracy because such rifles never break bolts, and it would therefore be entirely appropriate to source nitride 9310 bolts for such an application. Or if I were making race rifles, I would use aluminum carriers. Such decisions would be entirely reasonable, and the resulting product could very well be said to be high quality within its market, for its intended application. Putting such parts in a Mk18 going downrange, though, would be tantamount to premeditated murder.

Last but not least, boutique ARs are made for collectors. They’re like the custom motorcycles of the gun world. They’re more works of art and status symbols than a practical gun, and often sacrifice performance for aesthetics and features like being very small or very lightweight. Their aim is to be cool at any cost. A word of caution, though. Many a boutique AR masquerades as a duty grade AR, and due to the marketing on some of these guns the consumer might be forgiven for thinking these are serious guns for serious use. What further muddies these waters is that a lot of times this market serves as an R&D testing pool for products that might have real world applications, but are hitherto unfielded. The manufacturer may have developed the product to address an actual real world need, and they may in fact be seeking contracts, but the durability, reliability and compatibility of the product is largely unknown. The various PDW and folding stocks are a good case in point. There’s no question that we would all love a more compact stock/buffer system, and whoever manages to crack that nut will certainly profit from it, but until one gets put through large scale testing they will be firmly in the category of cool guns for the gram.

The real question you need to ask yourself is who the lowest common denominator is; i.e. what kind of user does this or that brand have to satisfy? When you do an image search for that system, what pops up: salty-looking professionals or models dressed up as special operations soldiers?

To flesh out that idea, imagine yourself as the manufacturer. Let’s say you serve the commercial market. Your typical customer is someone who’s going to buy the gun on a whim, mostly based on price and superficial features like furniture, and put a few hundred rounds through it a year. In other words, you know that 99% of people who buy your gun won’t shoot it enough to even begin to put it through its paces, much less wear it out. You also know that the worst consequence for failure is someone having a bad day at the range. If you invest 10% more in billets with a better grain structure, your customers won’t know, won’t care to know and won’t ever shoot enough to find out. And if your rifle is 10% more expensive than one that looks identical, or lacks flashy furniture, you’re going to lose that sale.

Now imagine yourself as the manufacturer of a rifle that is commonly used by military and law enforcement. When that rifle leaves your factory and goes to the distributor, you don’t know who the end user is going to be. It could be sold to a collector who will put it in his safe and never shoot it, or it could end up on the front lines in the Ukraine, in an officer’s patrol vehicle, etc. And if you skimp on the materials or QC to cut costs, your core customer will definitely notice when their organization’s guns start going down on the range.

If you’re the first category of manufacturer, it behooves you to cut costs on substance and then dress it up with nice furniture. Sure, that 1% of customers who actually shoot the gun might have the misfortune of happening to get a bad rifle, but that’s statistically unlikely. You don’t have to be a mathematician to calculate that the consequence of saving 10% on EVERY SINGLE RIFLE SOLD is that a mere 0.01% of them will come back for warranty. So you can save millions of dollars across the entire run, at the expense of having to replace one out of many thousands, resulting in a massive net savings to your company. Savings you can then pass along to the consumer to undercut the manufacturers of professional grade ARs that look identical on the surface and don’t have flashy furniture upgrades or mid length this or enhanced that…you get the idea.

And here’s the kicker. That tiny percentage of rifles that come back for warranty will actually result in free marketing for your company. Don’t believe me? Do this: google your favorite consumer grade AR and see what users are saying online. You’re going to see thousands of posts to the effect of, My (insert brand name) has been 100% reliable for (insert made up round count). Those are people who shoot 200 rounds a year, tops. And when you finally stumble on a post from the rare bird who put 2k rounds through one and had it fail, he’s likely going to say something to the effect of, While the rifle failed due to a bad part, the manufacturer went above and beyond to make it right! So even in the rare instance where one of these consumer grade ARs gets exposed for the lipsticked pig that it is, it usually results in an opportunity for that company to buy themselves some free positive press, and for simply doing the bare minimum that’s ethically required of them (i.e. repairing or replacing the rifle).

And when it comes to professional reviews, scant few are actually unbiased. First of all, truly unbiased reviewers who resist the temptation to sell out (who are rare birds indeed) still typically don’t badmouth anyone for the simple reason that it’s very risky. It’s socially, reputationally and even legally risky to call someone out. Not only could it result in a lawsuit, and often has, those who make their living doing reviews don’t want to alienate their audience. And the fastest way to alienate your audience is by badmouthing something that a lot of them probably have in their safe.

To illustrate, think about it this way. You’re a professional reviewer and you take about 20k dollars of your own money and buy several of the rifles and many thousands of rounds of ammunition, and you spend several weeks of your own time shooting, filming and scientifically collecting data. And you demonstrably prove that that AR is NOT in fact “just as good.” Well congratulations, you’ve just invested your entire production budget and a month of your time to lose a bunch of subscribers, receive lots of hate mail and probably get sued because you forgot to dot an i…and, well, we live in America, where anyone can sue anyone for anything…and you just attacked a publicly traded company with a full legal department at their disposal…and you’re a youtuber who’s best legal counsel is your uncle’s frat brother who barely passed the bar… You get it.

The world of reviewers, at least the successful ones (who don’t get sued), follow their mother’s advice: if you don’t have anything nice to say, don’t say anything at all. True independent reviewers pick out things they know they’re going to have something nice to say about, and avoid the ones they know they won’t. And if they do come across something they have nothing nice to say about…that’s right, they don’t say anything at all. Saying nice things gets views, people leave you nice comments, and, best of all, you don’t get sued! In the world of professional reviews, selling out or taking the high road are the only paths to long-term success.

In other words, don’t listen to the company’s claims or the claims of reviewers, independent or otherwise, and certainly don’t listen to the unsuspecting shills on the internet. Ask yourself, What motivates this company? Where is their incentive? Do they have an incentive to make quality products, or is their incentive to save money? And, to recap, you’ll find the answers to those questions by looking at who’s actually using the products. Ask yourself, Who is their poster child? Is it an Army Ranger or a chairborne ranger posing as a gun guru on 4chan?

Finally, choose substance over flash. That Colt M4 with its cringy FSB and 1980s furniture might not turn heads at the range, but the money was spent where it counts. Sure, the hobbyist AR next to it might give you fancy furniture for the same price or less, but who cares when it breaks a lug at 2k rounds. Furniture and doodads can always be added later, but a lemon will always be a lemon and no upgrade will change that.

The TL;DR is that “milspec” is an absolutely meaningless (and extremely misleading) marketing term, often used with the intent to fool unsuspecting consumers into believing a given AR15 is built to the same standards as a military issued rifle. The truth is that no manufacturer except for Colt even has the ability to make milspec parts because the TDP (technical data package) is owned by them, and is a closely guarded trade secret. Basically, the TDP is akin to the recipe for Coca-Cola. Lots of people make cola, and some may be as good, and some may be BETTER, but only Coca-Cola has the recipe for Coca-Cola. The same is true of AR15s. Most are varying degrees of jUsT aS gUd, some are actually just as good…and a scant few are objectively better.

If you have time to nerd out with me, here’s the long version:

The AR15 was originally developed by a company called Armalite, which was a small arms manufacturer that applied new technology from the emerging aerospace industry to firearms design, and essentially functioned as a research and development company, lacking large scale manufacturing capacity. They sold the patents and copyrights for the AR15 to Colt, who supplied all of the military’s AR15s exclusively throughout the 20th century.

As the patents ran out, others entered the marketplace with reverse engineered copies under different names (Colt continues to own the Trademark to this day). While these are dimensionally accurate clones that are even fully interchangeable with, and even entirely indistinguishable from, actual AR15s, they are not the same thing, in the same sense that you can make a cola that tastes identical to Coca-Cola, but may or may not be identical in fact.

The TDP, which is Colt’s “recipe” for manufacturing AR15s, is still a closely guarded trade secret. Due to the nature of government contracts, Colt supplies the TDP to various contractors, but according to the law those contractors 1) must pay Colt a fee for using the TDP, and 2) they must guard the secrecy of the TDP by keeping the assembly lines separate, and cannot sell any of the resulting parts to anyone but the government under the terms of that contract. So in the same way that Coca-Cola might outsource production to Value-Cola, Colt outsources production to AR15s-R-Us, but this does not make AR15s-R-Us parts the same, in the same way that Value-Cola labeled colas aren’t Coca-Cola just because they make actual Coca-Cola in the same factory.

So what then does “milspec” actually mean? Well that varies, but in general it means a “milspec style” bolt, which generally denotes a bolt made from carpenter 158 steel that’s phosphate coated. Generally speaking, it also means that they’re shot peened, high pressure tested and magnetic particle inspected; but there are shades of gray, and it could just simply denote that’s it’s a standard type bolt, vs. one of the myriad “enhanced” style bolts. What milspec does not denote is quality. Milspec labeled bolts include everything from pure garbage to peak performance, and everywhere in-between (and oftentimes the difference is mere luck of the draw).

This is where we get into the games that manufacturers like to play. For example, let’s talk about high pressure testing. According to the pre-2010 milspec, every bolt was high pressure tested (HPT). That’s an old habit in the firearms industry going back to medieval times. You’ve probably seen old world guns with strange little symbols stamped on the barrels; those are proof marks from the high pressure testing that’s still legally required in most of Europe. Today, it’s actually counterproductive to high pressure test every single part. Because of greater consistency in manufacturing technologies, we no longer have to test every single one of something. High pressure testing shortens the lifespan of something, so it’s better to pull one or several randomly from a production run and test those, and then discard them. This is known as batch testing.

Well, the issue is that batch testing isn’t standardized. What defines a batch, how many per batch are tested, what collection methods are used, etc. is all left to the imagination. What it all boils down to in the end is that you have to trust the company you’re dealing with to design their own QC procedures with the intent to produce the best product possible, vs do the bare minimum to be able to stamp that HP on their bolt without potentially committing fraud, and that bar is very low. They may have tested a bolt in 1995 using a proof load with one extra grain of powder and then marked every subsequent bolt HP after that.

The same is true of magnetic particle inspection and every other aspect of the manufacturing and QC process. At the end of the day, it all boils down to trust. You simply have to deal with companies that have a long track record for making good products, and that’s where Microbest comes in. Are they milspec? No. We didn’t steal them from a government arms room, and they are therefore not milspec. BUT, we have reason to believe they are as good as (or likely better than) actual milspec bolts. Microbest is the company that other reputable companies turn to for their AR15 bolts. They are a reputable company’s reputable company, as it were, and I’m thankful to be able to supply them to my customers.

You’ve probably heard or been told that most AR15s are “overgassed,” meaning that the gas port is excessively big, resulting in a variety of things we can file under the general category of no es bueno.

The TL;DR is no, milspec ARs are not overgassed. Some, many or most commercial ARs are overgassed because Joe Sixpack will complain that his H2 buffered 10″ pistol won’t cycle Tulammo in the Alaskan winter (.223 is slightly less caliente than 5.56 NATO, and el cheapo .223 is even less so).

Thus, commercial AR manufacturers learned a long time ago that it’s simply easier to enlarge the port and drop the buffer weight (saves money on tungsten) so that their guns will chew through the mildest ammo on the wintriest Alaskan night without complaining.

So where did the notion come from that milspec guns, specifically, are overgassed, overimpinged, etc.? Answer: people trying to sell doodads. Yes, it is in fact really that simple. When Colt is selling bomber rifles for seven hundred beans out the door, competitors have to do some pretty serious mental gymnastics to justify spending three to five times as much.

The truth is that milspec ARs CAN function with less gas, in MOST conditions, under MOST circumstances; BUT that doesn’t mean they’re overgassed. Milspec weapons have to function all the time, and there’s some variation in cartridges by a few thousand psi. Ammo lots are QC’d to run between a certain range, and a milspec AR has to cycle a cartridge at the bottom of that range in a dirty gun on a cold arctic night with the weapon pointed directly downwards, and still lock back.

So yes, that leaves some room, most of the time, to be able to restrict the gas flow, move the port forward and increase the buffer and or spring weight. Which makes it a little softer-shooting and a little less gassy with a suppressor. With the tradeoff being it might not cycle under certain conditions. Meaning that AR that’s been stone cold reliable on the flat range in fine weather might suddenly give you trouble if you have to defend yourself from an elevated position in the winter (think Rooftop Koreans: Detroit Edition).

If you run a suppressor full time and never take it off, there might be room for improvement. None of the military’s ARs were ever developed with full time suppressor use in mind. That said, suppressors aren’t barrels, and the impulse from suppressor back pressure isn’t the same. If you’re tuning your suppressed rifle to noticeably cut down on gas to face, you’re likely running things on the bleeding edge of what’s functional.

Finally, to play devil’s advocate, you should be looking at a flow-through style suppressor for your ARs, being that port pop is the limiting factor, especially with SBRs. That is, the sound from the port uncorking the spent case is going to be louder than the muzzle report anyways, so there’s only so much juice to be squeezed at the muzzle end. Ergo, there’s no point in having a super high efficient can that’s cutting your muzzle dBs to 120 when your port is throwing out 140 right next to your ear. Not only that, super efficient cans actually INCREASE port pop, which is obviously counterproductive, so it’s better to just get a low back pressure can that tames the muzzle blast down to baseline port pop levels, that doesn’t gas you out and that doesn’t affect the cycling of the action or require fancy doodads to switch between suppressed and unsuppressed modes.

As discussed here, AR15s were primarily designed to take less time to unlock, which allows for the carrier to start moving later in the gun’s cycle, which is extremely advantageous for accuracy and reliability.

As part of this overall strategy, there is no “runway” built into the carrier’s cam slot, meaning the nanosecond it starts moving to the rear it begins engaging the cam pin, thus unlocking the bolt.

The issue that arises is that carriers bounce off the breach when they slam home, and that few millimeters of bounce, as stated, will start to unlock the bolt.

Note that ALL automatic guns suffer from bolt bounce. Even the legendary AK47, given directly to Mikhail Kalashnikov by the Scythian gods themselves, suffers from bolt bounce. Yes, you heard that right, even Mikhail Kalashnikov can’t defy the laws of thermodynamics.

That few millimeters of bounce is compensated by a few millimeters of “runway” in the carrier’s cam path, meaning the cam path doesn’t actually engage the cam in the bolt within that distance.

The tradeoff, though, is that the carrier has to start moving even earlier to compensate for that margin, meaning you have to tap the gas from the barrel earlier, the piston moves earlier, etc. All of which is bad for reliability, durability and accuracy.

The AR solves this problem by solving bolt bounce altogether. The buffer is essentially a hollow metal tube with a weight that slides freely back and forth inside of it. It’s literally just a dead blow hammer.

Besides the potential for an out of battery detonation, bolt bounce is also not conducive to reliable cycling, especially in multi-shot modes. If the hammer outruns the carrier’s return post bounce, it will result in a stoppage. Fast hammers are preferable for accuracy; the longer the hammer takes to detonate the primer, the more time there is for the shooter’s muscle movements to pull the gun off target.

Long story short, the buffer isn’t a bandaid for an AR specific deficiency, as is often claimed. Annoying as it is, the buffer, bane of foldy boi enjoyers everywhere, is part of why the AR15 is superior to everything else.

The AR15 was and is the most technically advanced autoloading rifle ever designed. It solved a host of mechanical drawbacks that existed in most autoloading rifles, both then and now. The one we’re concerned with is the large bolt rotation angle in rotating bolt designs like the M14 and AK47. Most designs used two lug bolts, which required long cam paths and a lot of time to unlock, which equals no es bueno for a bunch of complicated sciency reasons.

The AR15 solved this problem by borrowing from the Johnson rifle and adding more lugs. The bolt didn’t have to rotate as much to unlock, meaning it could unlock faster because the carrier didn’t have to travel as far, leading to greater accuracy and reliability. And to cartridges with higher chamber pressures, enabling the poking of small holes in Russian helmets at greater distances (raise your hand if you ever dreamed THAT would be relevant again in the 21st century).

The downside is that the lugs were more delicate. This wasn’t a problem with Armalite’s AR15, or the numerous M16 variants that were put into service for the duration of the Cold War. It was, however, a problem with shorter variants that started popping up in the Vietnam war. However, these sawed-off variants weren’t especially prized at the time, at least not outside of certain skydiving clubs, and M16 bolt carrier groups would outlast the barrel. Several barrels, actually…by which time the receivers themselves would be toast. In other words, the M16 would outlast any other assault rifle at the time by about a factor of four, and the bolt carrier group wasn’t even the weak link. Thus, improving it was an answer to a question that almost nobody was asking.

Moving past the Cold War, though, two things happened. First of all, people got too lazy to march into battle, and, well…it’s very awkward getting into a car with a twenty inch barrel. Pretty soon, though, the problem got even worse. People couldn’t even be bothered to go outside to fight wars anymore, preferring instead to fight from their living rooms (and thus was born urban warfare). And if you think twenty inch barrels were inconvenient for getting in and out of cars, just imagine trying to conduct combat maneuvers inside the confines of someone’s living room.

Obviously, the niche sawed-off variants of the Vietnam war started looking a little more attractive. And as things got progressively shorter, the old problems started rearing their heads again, in the form of broken bolts and cam pins.

As these guns were widely fielded, it became apparent that the breakages could be unpredictable and random, occurring at any round count, despite preventative maintenance. The industry immediately set about designing a better mousetrap, and this became the LMT enhanced BCGs that were later further refined by KAC as the SR15. While these solved some hitherto unrealized design flaws with the AR15 bolt, namely the counterproductive lug opposite the extractor, they were expensive as all getout, and not at all backwards compatible with legacy weapons.

While all that was happening, though, incremental improvements were being made by Colt with the existing BCG, mostly in the form of better quality control and refining the heat treat method. This resulted in a few minor tweaks to the TDP, which produced a milspec bolt that could reliably outlast any barrel. See, barrel life goes down exponentially with length. A twenty inch barrel could last fifty thousand rounds, while a ten inch barrel was pretty well cooked at a mere six thousand. Barrel swaps typically necessitate bolt swaps regardless, and thus the enhanced bolts were never put into service.

This isn’t to say that unpredictable failures were stopped altogether, as evidenced by the fact that many Special Forces units still require the carrying of spare BCGs in the field. The failure rate was just reduced to the point that adopting a new AR variant wasn’t seen as a good use of funds, especially given that the AR15 platform and 5.56 NATO cartridge were already looking to be replaced by that time.

Fast forward twenty years later, though, and the AR15 is still the dominant issued platform for all of NATO, with no end in sight, in its 5.56 NATO chambering no less. And attempts to find a new standard has resulted in a proverbial herd of cats, with every NATO member and its units all pulling in different directions. The SCAR, HK416 and now the XM5.

Worse yet, the commercial market has also yielded to sub sixteen inch variants being the norm, with bolts of varying-but mostly dodgy-origins. And because of stuff and things, those dodgy commercial variants are now being widely fielded by, shall we say, NATO adjacent organizations.

And even if the AR15 is usurped as NATO’s main squeeze, this process will be slow, and support units and NATO allies will be inundated with used-up hand-me-down Mk18s that might be a warm day away from shearing a bolt lug, especially since they’ll probably come with the new extra spicy M855A1 cartridges that replaced the standard pressure M855. It was really nice of the Army to leave us that little treat right before leaving the party, huh?

American civilians will be in the same boat. While M855A1 isn’t common on the commercial market YET, there’s nothing legally preventing M855A1 from being sold commercially, and while certain political forces don’t want that, economic forces generally prevail. The government likes buying things cheap, in quantities from approximately one to one gazillion, to be determined by the declaration, or lack thereof, of WWIII. In other words, the manufacturer must produce one gazillion units with the knowledge that there’s a 99.9% probability they will sell only a small fraction to the government, with the rest usually being sold to the American consumer. In a few years, Lake City will be sitting on warehouses full of M855A1 that the government won’t be ordering, and everyone’ll be itching to slap an XM sticker on it and surplus it out to recoup their investment. With the next highest bidder being African warlords, the political forces generally end up conceding that it’s best to let it go to Americans, being that they will safely destroy it by way of dirt berm, rather than using it for other, less politically expedient purposes, such as genocide.

In conclusion, the AR15 BCG problem is not only not going away anytime soon, it’s going to get a lot worse before it ever gets better. And even if you as a soldier or civilian have your rifle squared away, the guy in the trench next to you might not. So you best get used to carrying spare bolt parts, and I humbly submit the ARFAK is by far the best way to do that.