Ladies and Gentlemen, and also my usual crew of readers, we are in an ammo crunch. Bullets are flying off shelves, and it probably isn’t going to get any better anytime soon. So I am taking this opportunity to address a question I have had since the last ammo crunch. Is there a way to train with my AR using rimfire only?
Why would I want to do that? Because centerfire seems to be harder to get and more expensive by a margin than it was just two months ago. Basic market forces are at work here. We have a gaggle of new shooters (welcome by the way), as well as people that never bothered to stockpile starting to stockpile. So not only did the cheap 5.56 go fast but manufacturers have no incentive to discount what is available. Coupled with rising raw materials cost, ammo is both harder to find and more expensive than it was. That makes me loath to burn up my own personal centerfire stock, as it is going to be hard to replace now.
Also I, like many of you, have been laying in 22LR since the last time. I can pat myself on the back for seeing the future exactly once, but it happened to be prior to the 2008 election. When 22 was nonexistent, I had enough. But I never forgot that feeling of not being able to get more. I’ve made it a point to get more at every turn, to include the now legendary Federal Black Friday rebate sales. So we, as in the Royal We, probably all have a gaggle of the deuce-deuce.
But what else did I learn last time? There is nothing quite like being able to train with my personal AR. I had a 10/22 and a couple of bolt actions. And I’ve toyed with some purpose build 22LR AR-15s. But I wanted a solution that worked for my precise gun. My trigger, which happens to be a quite pricey aftermarket AR Gold . My grip and stock. All the bits that make my gun feel exactly like my gun. Was that asking too much? Apparently no, it was not.
In the time between now and then, I have dug up two possible solutions to the problem. They are wildly different approaches, but both are going to solve the problem. First up is a CMMG Bravo drop in conversion kit, that simply replaces your bolt and magazines. Second is a Nordic Components dedicated 22LR upper. I see this as not so much a direct face-off, but two separate tools depending on your needs. Both have strengths and weaknesses, as testing showed. But both got the job done.
CMMG BRAVO
The CMMG Bravo, as mentioned, is a brilliantly simple design. It takes the place of your bolt carrier group, complete with a 5.56 shaped chamber insert on the end to take up the slack space a 22LR round would leave. The conversion kit is straight blowback with self-contained springs, so it doesn’t need to push your buffer back. And while I was skeptical, it ran amazingly well.
Strengths:
First off, the price is absolutely right. The CMMG Bravo has an MSRP of $229, which is a steal considering it comes with 3x 25 round magazines. You can often find them on sale, and I think mine was around $160 real-world price. That is a cost that really makes you wonder if it works. Which brings us too…
Reliability was amazingly good. I don’t think I had a single malfunction with the Bravo, and I shot it a lot. At the price, that is absolutely stunning. This is so cheap, you pretty much have to have one. It costs less than a 10/22, or almost any bolt action besides a Crickett.
Size and weight are a huge advantage of the CMMG. What originally caught my eye with this conversion kit was the potential to toss it in the go-bag. At less than the weight of a spare bolt, you gain a different caliber. 22LR is not my favorite combat round, but it beats the pants off a slingshot or Rambo knife. A CMMG conversion and a brick of 500 rounds is a pretty light addition to your survival kit and brings a lot of capability.
Weaknesses:
Are there downsides? Yes. First off, the CMMG uses your existing AR barrel, with either a 1:7,1:8, or 1:9 twist. Most 22LR rifles use a 1:16 twist. I think we can see the problem developing here. You can’t expect the CMMG to deliver accuracy on par with a correctly barreled gun. We will see more on that in a minute.
Second, we have a factor that affects both accuracy and suppress-ability. What is the diameter of a 22LR round? 223. Now guess what the diameter of a 223 Remington round is. If you said .224, you win a prize. (I also recommend a 2021 Congress of Shooters where we rename all bullets to reflect actual dimensions.) While that makes absolutely no sense, it is what it is. So a 22LR bullet is slightly undersized for an AR-15 barrel. Is that a huge deal? No. But does that mean we are going to have some inherent instability since the bullet isn’t engaging the lands and grooves fully? Yes. Does that make the risk of a baffle strike go up significantly if we try to use a suppressor? I can’t prove it, but I’m not risking one of my cans to find out.
The last weakness has a direct link to that same issue. Not only are we shooting lead bullets out of our AR barrel, but they are bouncing a bit. I would think that leads to barrel leading problems if you shoot a gaggle with it. This would be easily corrected by a thorough cleaning, I’m not concerned about the lead bullets damaging the barrel. But cleaning is something you absolutely want to do before you chuck more high velocity 5.56 down the tube.
Nordic Dedicated Upper Receiver
Nordic has been building high-quality AR-15 and shotgun parts for a very long time. So it stands to reason that they could build a high quality 22 Upper. Available in both 9.5-inch pistol and 16-inch rifle configurations, this solves a lot of the problems of a conversion kit.
Strengths:
Basically, it mitigates all the weaknesses of the CMMG kit. The barrel is the correct 1:16 twist. The barrel is the correct diameter. You can suppress it, no problem. And who cares if it gets lead in the barrel, it will never have a centerfire rifle round behind it.
Weaknesses:
First of all, is the cost. The Nordic is right at $500, with one 10 round magazine. That is a lot of dollars for a 22 upper, and more than many standalone rifles. Second, the Nordic requires proprietary rail segments, if you want some of those. And while Black Dog Brand magazines are available in quantity and size, you still gotta buy your own.
I bought some new 32 round Black Dog magazines, as they are recommended by Nordic. And if you watch the video, that is where I ran into some reliability issues. Now some of this is on me, as I bought a new design of said magazine. But it is the recommended brand, and I did have some problems. The new 32 was very tight in my Aero lower, though they fit fine in other AR brands. And they did not work well for me. The 10 round the Nordic shipped with had zero malfunctions. But I can’t say the same for the big sticks bought.
Accuracy Testing with both:
While the Nordic Components upper is available as both a 16-inch rifle and 9.25-inch pistol upper, only the 9.25 inch was available. I ended up at the range without a bipod and shot groups off a backpack. And while a backpack rest is pretty good, I do find myself more accurate with bipods. To be fair, I then dropped the CMMG kit in a 10.5-inch pistol upper and shot it the same way. So while I think this test was pretty close, I would not be surprised to find either system had a bit more accuracy in it.
I was using a Leupold Mk 5 for glass, which is a stunning amount of overkill for a 50-meter accuracy test. Hopefully, it made up for some of the less than ideal positions. I also was not using match grade 22LR, as I figured most people using an AR would be using bulk available ammo.
Across 3 samples of CCI and 1 of Federal, we found a predictable end result. The Nordic was more accurate, by a significant margin. It averaged around 1.25 inches, while the CMMG was closer to 3 inches. Is that enough of a difference to justify the cost of the Nordic? For some of you. And in some applications. But what I conclude is this.
These are both excellent solutions to the problem. The strengths of each play to a different segment of the audience, but both work very well. If you just want to plink around occasionally, and on normal sized targets, the CMMG is good enough. If you are shooting 10,000 training rounds per year, and are going to buy dedicated smaller steel targets? Nordic all day long. But either way, you are going to come up a winner with either purchase.
You can buy .22LR barrels so you can build a dedicated upper around the CMMG if you want.
This is great, more very useful gear I would have never known I needed if it weren’t for the Guns America blog… Thanks Clay!
Couple of comments. I shoot a lot of .22 suppressed and otherwise. From high twist CMMG conversion ARs and standard rifles and pistols.
First, a SAAMI spec .22lr is about .2255 diameter, the lands on a .22 rifle are about .216 and on a 5.56 AR, around .218. These vary by manufacturer. So no, a .22lr will not bounce around in an AR barrel.
What it will do is get over spin, creating inaccuracy for the light bullet. It Is unlikely to be unstable to the point of a baffle strike. Never had one from over spinning. But firing 40gr rounds from my CMMG with 1:7 twist sucks.
Now, here is the solution. 60gr .22lr Aquila SSS rounds. When fired from a 1:16 twist barrel, std .22lr, they very likely will baffle strike eventually. But when fired from a high twist AR barrel, they stabilize well, cycle well, and provide good accuracy.
You effectively have a 60gr subsonic round for suppressed applications.
You can also get fast twist barrels For the 10/22 specifically for these rounds.
BTW, when the SSS Ammo’s is fired from my AR platform, with the CMMG, through my average suppressor, the sound of the action Cycling and the impact on the target 25 yards away are louder than the muzzle report, significantly.
So, base you rifle selection on your ammo + Barrel twist. And your AR with a conversion is dependent on that, since the lead .22 will certainly engage the lands.
Excellent accurate factual instructional for all consideration in “conversion kits”. Lucky me, shot 1,000’s .22LF CCI 1,670FPS and other branded Ammo with +- “1” accuracy from DPMS Sporter .223/5.56 labeled barrel at 50 yards consistently with Leaper 3×9-40 Bug and 6×24-50 scopes. Spray bore clean chemical & then running a bore cleaning snake thru 3-4x with zero accuracy affected. I’ve swapped the CCMG over to other AR-15 that “ sighted in” and replicated consistently and consider myself a far shot with corrected vision thru Lasiks, PRK, and now cataract Vivity lense in my right eye-6 months lousy intermediate and far vision, but excellent up close vision-> open and especially accurate scoped anything. Thanks for the accurate details and please keep sharing wherever the posts are contributed.
Disability Ret Federal agent /LEO, armorer & firearms instructor in past lives (: Constitutional Carry for ALL USA States, districts, and Territories NOW, Forevermore as Our Forefathers created USA Constitution AND Bill of Rights !!
Clay, I run a few rounds of 556 down the tube after a couple passes with a bore snake. It seems to work well to avoid the leading issue. I’ve probably run 6-8000 rds of federal semi auto 22 thru my CMMG conversion kit and ar pistol barrel.
Cmmg also has dedicated uppers…..back to the range Clay!
I used the CMMG kit in a Daniel Defense rifle and found the grouping to be 4” at 25 yards with CCI Clean. It ran ok, but there was also shifting in these groupings. Some would group higher, lower, left and right. It’s absolutely fine for CQB training, though. It just didn’t work well for steel challenge.
I ended up ordering a CMMG 22lr barrel and an upper receiver. This removes the need for the chamber insert and utilizes a “collar”. Accuracy went up greatly and now shoots the same ammo under 1.5” with consistency and no shifting of the groups.