AR15 vs AR10 , Is Bigger Really Better? A Look at Big vs Little ARs Downrange

Tom compares the AR15 vs AR10 rifles when shooting at long range, and provides data for what happens to bullets as they travel downrange.

So what are the real differences between "big" and "little" AR rifles at longer range? Let's find out.
So what are the real differences between “big” and “little” AR rifles at longer range? Let's find out.

USA –-( We can all probably agree that AR-type rifles are great for shorter ranges, say zero to a couple hundred yards. But what happens when you start to move out to 400, 600, 800, or even 1,000 yards? Will an AR-15 rifle reach that far with the right ammunition? Does an AR-10 rifle chambered in a larger caliber like .308 or 6.5mm Creedmoor make that much difference?

AR15 vs AR10

Let’s take a closer look using a couple of example rifles. First up is the Aero Precision M4E1 rifle with a 16-inch barrel. As a “big AR” comparison, we brought out a Smith & Wesson Performance Center AR-10 chambered in 6.5mm Creedmoor. Last, as a “classic” AR-10 example, we used a Stag Arms Stag 10S AR-10 chambered in .308 Winchester.

For each rifle, we’ll choose one type of ammo that’s reasonably representative of the caliber for comparisons. We’ll make an exception for the .223 / 5.56 and use a 55-grain “standard” and 77-grain “long-range” option.

Also, keep in mind that the performance numbers here are from my exceptionally low altitude of about 30 feet above sea level. If you live just about anywhere else, your performance numbers will be better, meaning that your thinner air will allow bullets to fly farther faster.

So, when you leave the world of factory labs and special testing barrels, what will those rifles do in real-world conditions? Let’s compare some of the common performance attributes.

The significant difference between the AR-10 and AR-15 when it comes to long-range performance is the cartridge options that open up from the larger (longer) magazine well and bolt structure.
The significant difference between the AR-10 and AR-15 when it comes to long-range performance is the cartridge options that open up from the larger (longer) magazine well and bolt structure.

AR15 vs AR10 Velocity

So what do the big and small AR rifles deliver in terms of velocity, not only at the muzzle but well down range? We used a Shooting Chrony Beta Master Chronograph placed 15 feet in front of the fiery hole to measure the actual velocity and calculated the ddownrange speeds based on the specific bullet type and atmospheric conditions.

Again, since this shooting was done near sea level, if you live in a higher elevation, you’ll likely see that velocity carries significantly farther than what’s shown here. 





American Eagle AR223 55-grain .223 Remington





Norma Match-223 77-grain .223 Remington





American Eagle Open Tip Match 140-grain 6.5mm Creedmoor





Sig Sauer Open Tip Match 168-grain .308 Winchester





AR15 vs AR10 Energy

Kinetic energy is dependent on bullet weight and velocity. The velocity component is where things get tricky. Heavier or lighter bullets don’t necessarily carry velocity down range better or worse depending on their weight. That really depends on their ballistic coefficient, or in simple terms, how slippery a bullet is in the air. A longer and more slender but heavier bullet may have less velocity loss down range than a lighter one that’s faster at the muzzle but less aerodynamic over its entire flight path. In the velocity chart above you can see that while the 6.5mm Creedmoor doesn't start the fastest, it's winning the velocity game when you get out past 600 yards.





American Eagle AR223 55-grain .223 Remington





Norma Match-223 77-grain .223 Remington





American Eagle Open Tip Match 140-grain 6.5mm Creedmoor





Sig Sauer Open Tip Match 168-grain .308 Winchester





AR15 vs AR10 Bullet Drop

Gravity is gravity, and as some apple-eating guy figured out, weight doesn’t matter either. If you remove air resistance from the equation, a feather and brick will drop to the ground at the same rate of speed. So when it comes to bullet drop, projectile weight doesn’t matter. What does matter is the time that a given bullet is exposed to the forces of gravity over a certain distance. If one bullet makes it to the 1,000-yard mark faster than another, then it’s exposed to gravity for less time and will drop less. As we saw in a previous chart, higher velocity at the muzzle doesn’t necessarily mean that a speed advantage will carry down range. An aerodynamic bullet can start slower than another but finish faster because it carries it’s velocity over distance more effectively.

For all the loads shown here, we zeroed the rifle at 100 yards and used an optic with a crosshair 2.8 inches above the bore. 





American Eagle AR223 55-grain .223 Remington





Norma Match-223 77-grain .223 Remington





American Eagle Open Tip Match 140-grain 6.5mm Creedmoor





Sig Sauer Open Tip Match 168-grain .308 Winchester





Shaquille O'Neals
Shaquille O'Seals

Ponder those figures for just a second. At 1,000 yards, there is a 16-foot difference between the 6.5mm Creedmoor AR-10 and a standard AR-15.

That's over two Shaquille O'Neals tall.


To keep things simple, let’s assume we’re experiencing a 10 mile per hour crosswind coming directly from the three o’clock position. This chart shows how many inches each bullet will blow sideways at varying distances down range.





American Eagle AR223 55-grain .223 Remington





Norma Match-223 77-grain .223 Remington





American Eagle Open Tip Match 140-grain 6.5mm Creedmoor





Sig Sauer Open Tip Match 168-grain .308 Winchester





What about AR recoil?

All good things in life come at a price. So if you want more energy or velocity, your shoulder is going to pay. There’s a whole lot of complex rocket surgery behind measuring recoil, and much of it depends on the velocity curve of the recoil impulse. However, for a rough comparative guideline, we can look at recoil energy. This measurement takes into account the weight of the rifle (we’ll assume eight pounds for all rifles here), the bullet weight, powder charge weight, and velocity. All outputs are in units of foot-pounds. 

Recoil Energy

American Eagle AR223 55-grain .223 Remington


Norma Match-223 77-grain .223 Remington


American Eagle Open Tip Match 140-grain 6.5mm Creedmoor


Sig Sauer Open Tip Match 168-grain .308 Winchester


Bottom line thoughts…

There’s a reason that so many the best AR15 scopes have the same drop compensation markings for .223 and .308. While not identical and subject to variance depending on bullet types and weights, the trajectories between the two calibers are fairly similar. If you simply want more the energy and momentum of a bigger and fatter bullet, then an AR-10 in the classic .308 caliber might be your Huckleberry.

Where things start to get interesting is with other caliber options presented by the larger magazine well and upper receiver components of the AR-10 rifle platform vs the AR15. With a structure designed to handle longer and fatter cartridges safely, all sort of possibilities open up. While there are others, 6.5mm Creedmoor is a great example. Perhaps that’s why we’re seeing so many AR-10 and other semi-automatic platforms adopting that caliber.

Tom McHale

About Tom McHale

Tom McHale is the author of the Practical Guides book series that guides new and experienced shooters alike in a fun, approachable, and practical way. His books are available in print and eBook format on Amazon. You can also find him on Facebook, Twitter, Instagram and Pinterest.

  • 32 thoughts on “AR15 vs AR10 , Is Bigger Really Better? A Look at Big vs Little ARs Downrange

    1. This article could have been made better is you included the Remington 6.8 SPC cartridge. Which is being considered as a replacement for the 5.56 cartridge currently in use. Otherwise a very good article.

    2. Should things go sideways and the ability to shoot through vehicles and barriers (like trees and walls) become important, there is no substitute for kinetic energy. The average 308 bullet weighs 3x the common 223. Try out the difference.

      1. That would make you a smarter guy, regardless of your economic standing.

        Because the Grendel easily equals or out performs all the rounds tested while still in an AR-15 platform, with very little recoil. It’s a winner all around that receives far to little acknowledgement.

    3. Would be very curious to see a head to head of the 6.5 Creedmore vs 224 Valkyrie at 600 yards…seems that conceptually the projectiles have similar balistic profiles…and a similar price per round…

      However at $1 per round, vs .30 at the Milsurp 62GrLAP 5.56(250m), and the 7.62×51 149Gr(500 m) at about .50 per, those are effective for close to medium range Red Dot or ACOG distances. IMO different purpose firearms…Run and Gun(tactical16-18″ barrels) vs Breathe and squeeze(20-24″ barrel)…also IMO starting to think bolt action.

      1. Definitely. I have a case of Federal 90-grain Match 224 Valkyrie just waiting on a rifle that is on the way soonish. Also, have a couple of 6.5mm Creedmoors at the moment so we’ll be able to do a head to head in an upcoming story. I haven’t done the math yet but I think the recoil on the Valkyrie is supposed to be half of 6.5mm Creedmoor all else being the same. Then again, 6.5mm Creedmoor isn’t bad on recoil to start with. Could be interesting for times when you want to see the impact without the scope bouncing off target? I’m anxious to try them side by side!

      1. Those numbers are what I actually chronographed from that rifle on that day in those weather conditions. You’re right, most .308 loads are faster and have more energy, but this one in this situation actually clocked in at that speed and the energy is calculated from that. Then there’s the difference between what it says on the box versus what you can measure at home from your own rifle. It’s always different – sometimes faster than the box number but usually slower.

    4. Kel-Tec does make the PMR-30, Hornady Critical Defense 45 grain FTX rounds work very well in it also. You have to use s 40 grain bullet or heavier. I’ve ownedone for about a year and half now and love it. Great lil .22 Mag pistol. Real reliable as well. Good looking in FDE and or black. Good luck hunting one down. They seem hard to find around were I live on Tx.

    5. You might want to look into the 22 TCM. It is a product of Rock Island Armory. You can obtain a semi-auto in a single column or a double column. Oh! by-the-way, you can change the barrel and recoil spring and shoot 9 mm ammo through the same gun. The conversion is very simple to do at the range. Also you can purchase a 22 TCM Rifle. It comes with a 5 shot magazine. However, the rifle can use the double wide magazine which the double wide Semi-auto uses. The 22 TCM pistol is a BLAST to shoot. Flame throwers anyone! I have fired hundreds of rounds through the pistol, both 22 TCM And 9 mm, without one mishap of any kind.

      1. I picked-up a .22 TCM – 9mm double-stack 1911 about a year ago and I’ve found it hard to shoot anything else since then. The .22 TCM is just that much fun! Like you mentioned, it throws fireballs and has virtually zero felt recoil. I haven’t even considered converting it to 9mm yet. It’s just to much fun as it is.

    6. I remember from when I was in the USMC, we had to qualify with the M16’s at 500 yards. Actually, 200, 300 and 500 yards). But when we worked the butts (where the targets are), you could hear the 5.56 Nato rounds still exceeding the speed of sound, as they all had that sharp crack noise, as they passed overhead and through the targets. Of course we had M16’s with 20 inch barrels though. So it leads me to wonder what changed from then to now.

      1. Nothing has changed. An 18-20″ barrel on a AR15 would have been a better comparison for a 1000 yard analysis. It’s still supersonic at 500 yards, even with the 16″ barrel. Speed of sound is 1125.32 fps at sea level.

        1. Exactly – everything varies too with environmental conditions and altitude, so this was a test here, using common gear and ammo, with on-site measuring of velocity and such. This is a total guess but I wouldn’t be surprised if the 20″ barrel got 150 or more additional fps at the muzzle.

        2. My apologies, how stupid of me, I saw 500 and didn’t see 1,000 in the charts. I think I needed some coffee before I spoke up yesterday. My eyes played tricks on me.

    7. Can somebody help me understand this comment regarding bullet drop “Ponder those figures for just a second. At 1,000 yards, there is a 16-foot difference between the 6.5mm Creedmoor AR-10 and a standard AR-15.”?
      Maybe Tom should have said, “A 194 inch drop (16 feet) difference between …..” Using feet in a comment when inches is used in the chart is just poor writing.
      The drop difference between the Creedmoor and the .308 is an even bigger issue to ponder. That .308 doesn’t do much better than the .223.
      Interesting how the Creedmoor kicks butt without a killer recoil.
      When are our snipers going to upgrade to the Creedmoor?

      1. There are many days when I am in fact guilty of bad writing, but today isn’t one of them – at least not for the example you cite. You see, I’m using a top-secret and highly dangerous writing technique called “Illustrative Blathering.” I learned it when I spent 5,110 days studying with Shaolin Prose monks. I was going to say 14 years, but I didn’t want to be accused of bad writing by mixing days in the preceeding sentence with years in the following one. You can never be too careful with life and death stuff like words.

        Here’s how it works. I could have stuck with inches, but most of us mere mortals have trouble visualizing 194 inches. “Seeing” how big 194 inches is almost as hard as visualizing 492.76 centimeters! Well, unless you’re French. Duh. Anyway, most people have a pretty good mental picture of 16 feet and an even better picture of two Shaqs stacked on top of each other. Think about it. If you were stuck on Isla Nublar, you know, where Jurassic Park is, and you were suddenly attacked by a huge T-Rex, you probably wouldn’t say something like, “Holy Crap! That thing has got to be 194 inches tall!” However, you might casually mention to your T-Rex-appetizer buddy, “Dang, he’s got to be twice as tall as Shaquille O’Neal. I wonder if he plays center or power forward?”

        So there you have it. By sharing this ancient writing technique I’m probably going to be in a world of hurt with my Prose Monk Dalai, but he’ll get over it as long as you promise not to tell anyone else.

        1. That was a great answer. Is it just me, or does it seem that some guys just can’t wait to find something to criticize? Like The Washington Post and Trump’s tie selection? I dunno.

        2. @Tom McHale, You have a terrific sense of humor. I take my writing cap off in your presence. I reread your .17 WSM article from a couple of years ago, here in the Ammoland archives. Now, I am wondering Ruger 7717 or Volquartzen IF-5. What are your thoughts on these?

          1. Thanks for the kind words! Ruger is making pretty darn good rifles for the dollar these days so it’s hard to go wrong. On the other hand, I’m a total sucker for anything Volquartsen. Pretty much everything they make screams “custom shop” and the little machining details are always impressive. I haven’t shot them both so I don’t have much to add in terms of practical accuracy. Maybe someone here does?

            1. @TM, Oh, oh, I am feeling the vorticular pull of gunbroker. Slow at first, just enough to tousle the hair…

        3. This is hilarious, and makes perfsct sense, except for one small detail. (you KNEW this was coming ,eh?)

          Shaq don’t stack. So using that as a f’rinstance don’t rock.

          the 194 inches wasn’t too hard, sixteen feet was crystal clear. But a Two Shaq Staq? No clue how tall that is.

      2. I shot High Power Rifle competition, 200, 300, 600 and 1000 yards with 30-06 chambered rifles, first a surplus Garand, later on with the Model 70 Winchester Standard Target Rifle. I never found the recoil of these rifles bothersome, and I was not especially big, 6 ft. tall, weighed about 160 lbs.

    8. Why can’t we develop a great .22 mag pistol, semi auto? I had an A MT .22 mag automag pistol that was awesome. I fired many rounds w/ o any complications, so, what gives??

      1. Have you tried the KelTec PMR? Might be what you are looking for. And they also make the CMR (carbine) which uses the same magazine.

      2. There is a 22 mag semi auto pistol. I’m sorry the make escapes me but check on line at a dealer like Grab a Gun or Bud’s. Go to pistols on their web page and plug the 22 mag in for caliber. I think in may be a Keltech.

        1. Yeah I have the Kel-Tec PMR-30. It’s a sweet lil .22 Mag pistol. Hornady Critical Defense 45 grain FTX rounds work very well in it also. Hornady I’d my preferred brand ammo for all my firearms. Only catch to the PMR-30 is you have to use 40 grain bullets or heavier for best preformance of the pistol. You can get it in FDE or Black. I own the FDE… Good luck hunting one down. Here in Texas were I live they are few and far to come by. Seems like they can’t make enough for the demand of it.

          1. Easy to find on line and sent to your local shop. A dealer had it on line for $339 earlier this week. Can’t remember who but maybe Smokey mountain.

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