There’s a question that I see pop up a lot in forums and social media: “How much should my AR-15 weigh?” The most popular answer is, “as light as you can make it.” While pithy, such a response is still valid up to a point. While I can provide some firmer numbers, and I will, it’s also important to consider the weight factor within a context of balancing other elements as well.
That said, we need a baseline.
The AR-15 Starting Point: 6.4 lbs
The M16A1 originally fielded in 1967 had an unloaded weight of 6.35 lbs. I’m rounding that up just a bit to 6.4 lbs. With a sling and loaded 20-round magazine, the weight came in at 6.75 lbs, or 7 lbs with a 30-round magazine.
I should note that this 6.4 lb weight standard comes along with a rifle that has an overall length of 38.8 inches, sometimes rounded up to 39 inches.
I think both of these numbers, 6.4 lbs and 38.8 inches, are interesting for several reasons. First, they represented a significant weight savings over the M1 Garand and M14 rifles previously adopted. The M1 weight 9.5 lbs unloaded, and about 11 lbs loaded with M2 ball and a 1907 sling. The M14 weighed 9.2 lbs unloaded and 10.7 lbs with a loaded 20-round magazine. The M1 and M14 came in at a length of 43.4 and 44.3 inches, respectively.
Jeff Cooper, the famed marksman, creator of the scout rifle concept, and author of many books, had a lot of opinions about how a rifle used in the field should be configured. He often opined that his “holy grail” weapon would weigh no more than 3.0 kg (or 6.6 lbs) and have a length of no more than one meter (about 39 inches). Any deviation from these two goals began reducing a rifle’s utility as an “athletic” instrument for use in the field.
While Mr. Cooper was particularly interested in hunting, I believe the same principles apply to a weapon intended for defensive use.
Further AR-15 and M16 Evolution
I should note that the M16 did not stay at it’s svelte 6.4 lbs forever. With the introduction of the M16A2, the new heavier “Government Profile” barrel and slightly longer stock increased the weight up to 7.8 lbs unloaded, and 8.5 lbs/8.8 lbs with a sling and 20-round/30-round magazine. While still lighter than the M1 and M14, it’s certainly heavier than the original format.
By the time the M16A4 rolls around in the late 1990’s, the extra equipment raised the weight to 9.08 lbs unloaded, and 10 lbs with sling and a 30-round magazine. Now we’re definitely encroaching back into the weight we lost by dropping the M1 and M14.
When the M4 Carbine came around in the early 1990’s, it once again brought the unloaded weight back down to 6.5 lbs due to its shorter barrel and collapsible stock.
To to bring this back to the original question: our target weight for an all-around AR-15 durable enough for just about anything we can throw at it from self defense to hunting and open conflict is about 6.5 lbs.
Now Let’s Talk Compromises
The trouble starts when we consider that all of these weights stem from rifles we call “bare bones” by today’s standards. For example, these weights only include iron sights and do not include any sort of optic or weapon-mounted light. Improved sights and a light are among the bare bones things I recommend for new AR-15 owners to invest in once they have a reliable rifle.
Today we have access to a variety of accessories that each add capability that we might want to have. Whether it’s IR lasers or vertical foregrips, powerful optics, or more- we can add a huge amount of capability. Nothing is free, however.
If you take the M16A4 at 9.08 lbs unloaded, then add a 2.1 lb 1-8x LPVO “Squad Common Optic,” an 8 oz DBAL illuminator, a 30-round magazine, sling, and anything else that might “bolt on,” you’re easily into the realm of a 13 lb rifle.
Now you’re seeing the problem.
In order to get the weight back down closer to our ideal range, you have to start making choices that reduce the weight. Maybe it’s starting with a smaller weapon like the M4A1 or M27 IAR, or perhaps it’s switching back to a skinny barrel. You might consider lighter weight furniture, or even going more extreme with lightweight components that shave off a few grams and ounces here and there.
Weight Isn’t the Only Factor
With everything I’ve said so far, it would be easy to focus only on the AR-15’s weight versus capability argument. Any conversation about this should also include two other factors: balance and reliability.
Too many people discount the importance of a weapon’s balance. Without repeating myself too much, the more a rifle balances to the front, the heaver it feels to handle and move with, but the more stable it will be during firing. The more rearward the balance, the quicker it is to point and move while it becomes less stable from shot to shot.
Everyone has a preference for what they like. I have absolutely selected a heavier stock for my AR’s that needed some extra help balancing to the rear, even if it meant harming the overall weight.
Now we get to the reliability and durability factor. Because so many people want to use the latest and greatest accessories, there’s a bit of a cottage industry around producing the lightest-weight parts we can engineer. That might be as advanced as carbon fiber-wrapped barrels, but it could also be as simple as skeletonizing the receiver.
The question you have to ask yourself is whether or not the “improved” part will hurt reliability or not. For example, I would simply never utilize a skeletonized upper receiver that could allow debris into the operating mechanisms of my rifle.
So You Want a Lighter AR-15? What’s Next?
To wrap this article up, let’s talk about where and how you should go about making these compromises. I want you to ask yourself two important questions:
- Do you need all of that stuff you’ve got attachd to your weapon?
- What are you willing to compromise?
The first question is a bit more straight forward. If you’re rocking an IR illuminator, but don’t actually own night vision- then you have uncessary weight. If you’re using a heavy LPVO optic, but almost never shoot beyond 50 to 100 yards, then you would probably be better off with a lighter weight red dot- or even a compact prismatic.
All I’m saying is make an honest assessment of what’s attached to your rifle and decide whether or not it is actually helping you do anything besides “look cool.”
On the second point, this is really a question of balancing capability and weight. One of the first places I would look for reducing weight is in the barrel. Notice that the switch from a pencil profile barrel to a government profile barrel contributed to over a lb of weight added to the M16A2 over the M16A1. The barrel also has a huge impact on the balance of a weapon.
So, if you don’t already have a lightweight barrel, what are you gaining from something heavier? Do you compete and have a need to put out a sustained high rate of fire with an accuracy demand? Do you have particular marksmanship goals that the added weight helps you better accomplish?
Most people are simply better off with a lightweight profile.
What about your rifle’s furniture? For most people, especialy if they aren’t attaching a bunch of stuff to the handguard, there’s nothing wrong with a quality set of lightweight polymer handguards. In fact, they still work just fine for things like mounting lights because many handguards these days also have MLOK.
Sure, you can get even lighter than polymer by going to some nicely machined metal units from quality companies, so go for that if you have the budget.
When it comes to the stock, this is really personal preference. You can go lightweight, my only caution is to keep balance in mind as well.
I do not suggest incorporating lightweight operating mechanisms like bolt carriers and stuff. Those have a time and place for specific conditions- but not on a rifle you need to stake your life on for defense.
To circle back to the beginning. For most people, a target weight of 6.5 lbs unloaded is perfect for an AR-15. Anything above that starts to include compromises. Some of those compromises are worth it, such as improved optics and lights, others are not. Always ask yourself if the thing your adding on and taking you further away from that goal is actually going to assist you and the way that you employ your rifle. If not, then it’s not worth the weight.