Awhile back ago we took a look at, 300 AAC Black Out 300 PRC, 6.5 Creedmoor and a few other popular long range cartridges. The purpose was to see if there was a real benefit to some of these cartridges other then marketing hype. We attempted to answer whether or not these cartridges filled a niche, or were obsolete before they hit the shelves.
Today we are doing something similar. We are looking at three different cartridges for the AR-15 Platform to see if we can figure out which one is superior for long range shooting. These cartridges are the .22 Nosler, the 6.5 Grendel, the 6mm ARC ( Nearly Identical to the 6mm AR), and the 224 Valkyrie. Each of these cartridges have been marketed as the ideal long range cartridge for an AR-15, and field results have been variable.
It should been noted that all of these cartridges outperform the 5.56x45mm or 223 Remington and it’s derivatives. Which is why I haven’t done any direct comparisons to this cartridge. While it has some advantages, it is outclassed by these cartridges when it comes to long range performance.
6.5 Grendal
The 6.5 Grendel was introduce by Alexander Arms in 2003. When first introduced it was a proprietary cartridge. Usually proprietary cartridges do not become commercial successes. However both 6.5 Grendel and 50 Beowulf have enjoyed moderate success. To the point where 6.5 Grendel was introduced and accepted as a SAAMI cartridge in 2011.
The cartridge fits comfortably in an standard AR mag, but the larger head diameter reduces the over all mag capacity by 4 on a standard 30 round magazine. Maximum average pressure (MAP) is 52,000psi. Typically the best long range performance is found with a 129gr or 130gr high BC Bullet such as a Sierra Match King (SMK). The practical range of these cartridge is often cited to be about 800 yards, however shooters have found good performance out to 1000 yards.
6mm ARC
The 6mm Advance Rifle Cartridge was introduce to SAAMI in the January 2020 meeting, and accepted in the June 2020 meeting. Of all the cartridges we will be comparing, this is the newest cartridge on the scene, and we have the least amount of data to work with. Comparing the cartridge drawing of the 6mm ARC to the 6mm AR we see two very similar cartridges but it would appear that the 6mm ARC is a little smaller, and a little shorter then the 6mm AR.
Hornady plans on releasing hunting ammunition in the fall of 2020. While target ammunition is already available. Given the popularity of the 6mm, and the the 6.5mm catridges as of late, it wouldn’t surprise me to see this become an extremely popular AR cartridge. This being the first SAAMI adopted 6mm cartridge being specifically designed for an AR-15.
(Whoops, I lied, the 6x45mm was accepted prior to the 6mm ARC, but it has never really taken off, being that it was just a 5.56×45 case necked up to 6mm, it likely is somewhat anemic compared to the 6mm ARC or 6mm AR. I have not run the numbers but looking at the case design, that is my first impression)
22 Nosler
The 22 Nosler was introduced into SAAMI in January 2017. My first of impression of this cartridge was similar to that off the rest of the “Nosler” family of cartridges. This was a cartridge designed to maximize the amount of powder and pressure you could stick behind a bullet, for a given action. The rest of the cartridges were based on 300 RUM (another cartridge designed to maximize powder capacity & pressure for a given action), however the 22 Nosler is it own unique cartridge with no parent case.
SAAMI MAP for this cartridge is 65,000psi, which is unusually high for an AR-15 cartridge. Most cartridges designed for the AR-15 stay below 55,000psi. Given the shell has a rebated rim, and is designed to be used with a standard AR bolt face, it makes you wonder how badly the 22 Nosler beats up an AR action.
The standard twist rate for the 22 Nosler is 1:8, which allows it to stabilize bullets up to 85gr. In a 22 cal this is a must, and gives it some legs as a long range shooter.
224 Valkyrie
This is an interesting cartridge, developed primarily by Federal. It was marketed as being “The” long range cartridge for an AR-15, boasting the ability to launch 90gr SMK’s at a little over 2600fps. (If you know me, I consider 2600fps to 2700fps a ballistic sweet spot). However the launch was pretty rocky and to this day it isn’t exactly clear as to what happened.
Federal has since revamped their ammunition working with Sierra, to produce a better 90 grain pill. These are long, and heavy for caliber bullets with high B.C. values. Some argue that 1:7 Twist wasn’t adequate to stabilize the 90gr bullets, however, the issues were had as sea level and in the mountains. Marginal performance due to a slow twist rate usually goes away as you get into the thinner air in the mountains.
People have began to use 1:6.5 twist barrels, and have found them to be successful. Still the question I have is if they are successful because the increase in twist rate, or are they successful because they are using a 2nd gen bullet/load that has been improved to the point where the issues were resolved. I do not know the answer to that.
Federal making bold claims about it’s performance, and then botching the launch has tarnished this cartridge. However it does appear to have some benefits over the 22 Nosler, the SAAMI MAP Pressure is lower, at 55,000psi, it is likely to be less harsh on an AR-15 bolt. Also the 1:7 standard twist allows for stabilizing heavier bullets. If the problems have been solved, we might see this cartridge stick around for awhile.
So I’m looking at Building a Long Range AR-15 Which Cartridge do I Choose?
That’s the question that really troubles a lot of people. I know I’d loose sleep over it, as all of these cartridges seem to have their merit. So let’s do some performance comparisons.
For these performance comparisons we used Ballistic Explorer to model the bullet’s flight. We used Sierra Match King bullets, and we tried to select the load the matched commercially available load and velocities. The BC data was sourced from Sierra and is variable dependent on the velocity of the bullet. The assumption for all the loads modeled is that they are being shot from a rifle weighing 8 pounds with a 24in barrel.
Crucial to any ballistics comparison is that we keep the atmospheric conditions the same for all the of the model. For the sake of this model, I inputted what might be a typical atmosphere where I live. Therefore the bullet drops, and the performance you get may not match what my model says. With that said, it is unlikely that a cartridge’s performance will change in comparison to another just because the atmospherics are different.
With all of the disclaimer stuff out of the way, lets take a look at the results. Ballistic Explorer only allows use to compare three traces at a time. So we will start with 6.5 Grendel, 6mm ARC, and 224 Valkyrie, the worse performing of the three will be dropped off and we will substitute in 22 Nosler.
I approach all of my comparisons with no bias, I want to present the data and then make an attempt to go through it with you. In this case we see that clearly the 6mm ARC appears to be the better cartridge from a ballistics standpoint. At 1000 yards, there is 32.41 MOA of drop compared to 38.50 of the 6.5 Grendel and the 34.75 of the 224 Valkyrie.
For the target shooter, we really don’t care too much about energy. The reason being, is if the bullet can pierce paper, we are happy. However the hunter must pay special attention to bullet energy. Bullet expansion and penetration into flesh relies on energy, not to mention it is the energy being dissipated into flesh that destroys organs, and breaks bones.
To give the reader a bit of perspective. The minimum amount of energy needed to reliably kill a deer is 1000ftlbs, an elk is 1500ftlbs. Please note the use of the word reliably, as you can kill just about any living thing will a .22lr, but it is difficult to do so unless you have proper shot placement. We will be using these standards to evaluate the effective range for hunting deer.
We can see in the above table that Trace 3 (the 224 Valkyrie) can be considered a 400 to 500 yard deer rifle. While the 6.5 Grendel and the 6mm ARC both extend that range to 500-600 yards. It is up to you as a hunter to decide if you can perform an ethical kill at those ranges, but those are the hard numbers.
Another metric that we can use to evaluate the performance of a cartridge where the cartridge enters the trans-sonic range. This is usually between 900 to 1200 fps. At speeds of 900fps pockets of air are reaching supersonic speed, at speeds greater then 1200 fps all of the airflow is supersonic. Usually for best results we want to keep supersonic air flowing over the bullet for as long as possible. As the airspeed slows, the shock wave begins to collapse which can unpredictably disrupt the bullet’s flight.
Some people treat this as an virtual wall, however that’s not true. All we are saying is that accuracy becomes a little less predicable as the bullet passes through this phase of deceleration. People have still shot excellent groups at with bullets that were subsonic at ranges past 1000 yards. Treat this as a marker as a mile stone in the bullets flight, where the longer it stays supersonic the better.
Base on these three performance characteristics, it looks to me that 6.5 Grendel is behind in two of the three metrics. It holds onto it’s energy a bit better then the 224 Valkyrie, but it does not hold on to it’s velocity and thus it drops a little faster then the other two candidates. So we will drop the 6.5 Grendel and replace it with the 22 Nosler.
Despite the 22 Nosler shooting a lighter weight bullet then the 22 Valkyrie, it has a much higher SAAMI MAP, which sends these bullets downrange at 2950fps. This means it outperforms the 224 Valkyrie in some, but not every metric. As we can see from the chart below, the 224 Valkyrie over takes the 22 Nosler in retained energy at around 500 yards. For the average deer hunter the 22 Nosler is still a 400-500 rifle.
Looking at the next metric, bullet velocity also gives us an interesting insight.
Despite the 6mm ARC overtaking the 22 Nosler in retained velocity, it still falls prey to the higher muzzle velocity of the 22 Nosler, resulting in 2 MOA less muzzle drop at 1000 yards. We can also note that the 22 Nosler also is safely above the trans sonic range of 1200 fps at 1000 yards.
Performance wise, I see these three cartridges as pretty darn close with the 22 Nosler and the 6mm ARC leading the pack. There is one more metric that I use when looking at a cartridge. That is anticipated felt recoil. This is important from a shooter’s fatiuge point of view. While neither cartridge will be as brutal as a 338 Lapua, some recoil will contribute to a shooters fatigue. More recoil, the less a shooter is going to spend time on the shooting line. While muzzle devices can help reduced felt recoil they typically come at a cost, a muzzle break converts recoil energy into sound. A suppressor, creates heat which can result in mirage, it also ads weight and length to the rifle which makes it a little more cumbersome to handle.
As mentioned previously we are assuming each rifle weighs 8 pounds.
Nosler 22 w/30gr powder charge and a 80gr bullet – 6.01ftlbs
224 Valkyrie w/28gr powder charge and a 90gr bullet – 5.68ftlbs
6mm ARC w/30gr powder charge and a 107gr bullet – 7.84ftlbs
6.5 Grendel w/29gr powder charge and a 123gr bullet – 8.75ftlbs
To give you and idea, the felt recoil on these rifles will be somewhere between a AR-15 and a AK-47. The recoils are quite manageable and most people will find it to be mild, and comfortable to shoot.
So what do I think?
If you follow the firearms industry for long you will see a few stand out companies when it comes to marketing. One of them is Hornady. They have a fantastic marketing department. With that said, the 300 PRC, and this new 6mm ARC cartridge, it looks to me like it isn’t just all hype. The engineers have a cartridge that is likely going to be the new hot thing, as long as it doesn’t run into issues like the 224 Valkyrie did.
In fact I might be so bold to say, that it makes the 6.5 Grendel obsolete, and it is pushing the 224 Valkyrie further back into the shadows. When it comes to the 22 Nosler I have two main concerns, the first being the pressure. AR-15’s were designed with the 5.56×45 Cartridge in mind, along with the pressures. When you do what Nosler has done, and jack up the pressure you will also accelerate wear on the rifle. I just don’t see an easy way around that one.
Nosler claims barrel life is between 2,000 to 4,000 rounds. That might seem like a lot until you realize that 223 AR barrel regularly go 10,000+ rounds and still run strong. They also don’t mention other components, such as the bolt. I have not looked into what is done at the port to reduce port pressure, we are stressing the bolt, and gas system with these higher pressures. I do not see anywhere that is directly addressed.
The second concern is muzzle blast. Muzzle blast sometimes fatigues the shooter but more often is an annoyance to those around the shooter. Higher chamber pressures usually translates to greater muzzle blast. Muzzle devices such as compensators only magnify the problem, as do shorter barrel lengths. You are not going to make any friends with this rifle.
The one metric I did not look at was cost. With the 6mm ARC being a brand new cartridge the brass and the components are going to come at a premium. 6.5 Grendel has been around awhile, the component cost has come down considerably. One of the things i preach is practice. People rely too much on a fancy rifle or optic, or a large big bore cartridge for long range shooting. To become proficient , you must put in the time on the range. If you constantly wear out barrels with the 22 Nosler, or the ammunition is so expensive you cannot afford to shoot, it you would be better off shooting a 6.5 Grendel or even a 223 Remington.
If I was to buy a rifle in any of these calibers, I would seriously consider the 6mm ARC. Not because I am a fan of Hornady. They don’t pay me a dime. (I’ll consider a sponsorshop *wink*wink) but because the ballistics look promising, it is using off the shelf bullet (I believe the 224 Valkyrie’s trouble was growing pains related to mass manufacture of a new 90gr pill) and it looks like there is large support for the caliber which means it’s likely to be around for awhile.
Those are my thoughts, do you agree? Disagree, have some pointers you like to add? Let me know!