I’m not the first person to say something like that.
I’m definitely not the most experienced AR shooter to say something like that (Recently, Mike Pannone published an article called “The Big M4 Myth” regarding fouling. I don’t want to claim any of his ideas as my own. If you see something that seems really intuitive, it probably came from him. In this article, I’m going to talk about the same subject, but with a slightly different approach).
And yet, the “clean your AR-15” mantra is repeated over and over, in gun stores, online, at shooting ranges, in military training, and so on.
Over the past few years, I’ve fired a number of ARs (and a number of other weapons, for that matter) for thousands of rounds without any sort of cleaning whatsoever – in most cases, I just kept adding lubricant to the weapon. Recently, as you can see right below this post, I fired close to 3000 rounds through a 5.45 AR-15 without cleaning or lubrication.
“But how?!” you say. “The AR-15 ‘defecates’ where it eats! I know this because people on the internet have been saying it!”
Well, I don’t want to spend too much time describing how the AR-15 works – Steve at Adco Firearms does a pretty darn good job here.
What’s important to know is that the bolt is itself a piston – it even has rings just like the pistons in your car’s engine (unless you’re a Wankel fan). In other words, those rings need to have a good seal against the cylinder walls – the bolt carrier.
Every time the weapon is fired, the rings scrape carbon away from the carrier – the same goes for the bearing surface farther forward on the bolt (with the exception of the extractor, which must have room to maneuver, and therefore cannot serve as a bearing surface). Practically no carbon will build up on the areas where these components actually touch, even after thousands of rounds have been fired. This goes for the bolt carrier, too – where it contacts the upper receiver, it will be clean to the point that it appears polished.
Here are some photos to explain what I’m talking about:
Take a guess as to where the carrier contacts the upper receiver.
The contact points on the carrier are clean. Pretty much everything else is filthy. No big deal.
See all that carbon? Its presence is essentially inconsequential to the operation of the weapon.
It’s a bad photo, but you can clearly see the path traced by the extractor – rather, the path of carbon left where the extractor rides just beneath the forward bearing surface on the bolt. This bearing surface removes carbon from the rest of the inside of the carrier.
Here we see a very clear delineation between where the gas rings seal against the bolt – and where they do not.
What does all this mean?
Quite a few people are worried about carbon buildup. There are even companies that will sell you carbon scrapers – and of course, there are companies that will sell you an external piston/op-rod setup. Both have major drawbacks. Excessive cleaning can remove finishes which are important to the operation of the weapon. And eliminating the inline operating system, the “internal piston” as Armalite calls it, has a host of drawbacks that I won’t cover here and now.
The bottom line is that cleaning for the sake of reducing malfunctions is a waste of time. Cleaning may make the weapon prettier, cleaning may make you feel better – but cleaning will not drastically improve the reliability of the weapon, unless unrealistically large round counts are being considered. Even then, you would have a better chance of improving reliability simply by adding lube to the weapon, as shown by the single drop of oil in the cam pin hole of the 5.45 allowing the weapon to run for another 150 trouble-free rounds.What’s easier in the field – some lube, or a complete detail strip and scrape of every part with carbon on it?
There are reasons to clean your weapon, though – such as the corrosive primers used in surplus 5.45 ammunition, for example. Good finishes and metal treatments such as nickel boron and melonite should reduce this need, but only time will tell if it’s been eliminated.
Some people say that their AR only works when it’s perfectly clean. I say that if so, there’s something else wrong with the weapon. Some part is probably worn out – a spring, the gas rings, and so on – and needs to be replaced. Read Mike Pannone’s article for more information on that subject.
If your AR-15 is properly lubricated, and it’s malfunctioning, fouling is NOT the source of the malfunction.