Rock River Arms LAR-15 right side

Best AR-15 .22LR Conversion Kits

Do you want to get an AR-15 in .22 LR? But do you also not want to stomach up the money for an entirely new AR 22?

Best Pick for 5.7mm AR-15s: CMMG AR MK57 Conversion Kit with Magazines

CMMG AR MK57 Conversion Kit with 3 Magazines

The CMMG AR MK57 Conversion Kit is one of the best conversion kits for chambering an AR-15 in 5.7x28mm. This kit has a drop-in design that is very easy to install in mil-spec AR-15s, and as an added bonus, it comes with three 25 round magazines.

See on Brownells

Best Pick For 5.56 AR-15s: CMMG AR-15 .22 LR Bravo Conversion Kit

CMMG AR-15 .22 LR Bravo Conversion Kit

The CMMG AR-15 .22 LR Bravo Conversion Kit will replace the bolt and bolt carrier in your AR-15 to optimize it for the .22 LR round. This kit also comes with a 25 round magazine designed to fit .22 LR rounds as well, although it can be difficult to load rounds into at first due to the stiffer spring.

See on Brownells

Best Overall Pick: CMMG Echo SS Arc Kit w/ 25 Round Magazine

CMMG Echo SS Arc Kit with 25 Round Magazine

The CMMG Echo SS Arc Kit is an excellent choice for an AR-15 .22 LR conversion kit that provides you with a lot of features for the money. While the gray colored magazine is admittedly not the most appealing, you’re still getting a high quality conversion kit that’s easy to install due to its drop-in design. The magazine is also easier to load rounds into over several of its competitors.

See on Palmetto State Armory

If you are in this position, your next best option is to get a .22 LR conversion kit. A conversion kit will convert your existing AR-15 in 5.56x45mm NATO to .22 LR for far less than if you were to buy an entirely new .22 LR rifle yourself.

The .22 LR cartridge itself has been around since the mid 1880s, and today is by far the best selling and most widespread round worldwide. As a result, you should not be surprised that most other rounds can be modified easily to shoot the cartridge. The AR-15 is no exception.

In this guide, we’ll cover the merits of the .22 LR cartridge, why you would want to convert your AR-15 to .22 LR, the primary kinds of conversion kits, and the top qualities to look for in a conversion kit. Then, we’ll dive into the top three best conversion kits to get today.

The Benefits of the .22 LR Round

As noted previously, the .22 LR round was first introduced in the mid-to-late 1880s, with most sources agreeing that the round was developed and released between 1884 to 1887.

Today, the .22 LR is one of the most widespread calibers in use today. It shouldn’t be hard to see why: .22 is very affordable and it can be bought in bulk. It’s also a very small round, and you can stockpile literally hundreds or even thousands of rounds in a very small amount of space.

A box that could hold 50 rounds of 9mm, for instance, could store literally hundreds of rounds of .22. To put that into perspective, you can carry a significant amount of .22 LR ammunition on your body as you travel on foot without it creating too much weight. Speaking of 9mm, we also have an article about AR 9 conversion kits.

.22 LR also has the advantage of being a very low recoil round with less noise compared to other calibers. In other words, it’s very easy (and fun) to shoot and can cause less disturbance for anyone else in your vicinity.

Finally, the versatility of the .22 should not be discounted as well. Beyond being an excellent casual plinker, the .22 round is also adept as a general homestead round to kill varmints, a small game hunting round, and even for self-defense if you need it to be used for that purpose.

Why Should You Convert Your AR-15 To .22 LR?

So, why should you convert your AR-15 to .22 LR? Let’s just say this: there are more reasons than one.

As noted previously, .22 LR ammunition is usually low cost and can be bought in bulk. In other words, most people can afford to shoot it far more often than they can standard 5.56 rounds.

By shooting .22 LR out of an AR-15, you will be shooting a rifle that has the exact same manual of arms as your normal tactical rifle. In contrast, the alternative option would be to use a .22 rifle such as the Marlin Model 60 or the Ruger 10/22. While both of those are good rifles, both of them have a manual of arms that are definitely different from the AR-15 as well.

An AR-15 in .22 LR can therefore be an excellent training tool for when you don’t want to shoot the more expensive 5.56 ammunition (or any other caliber that your AR shoots). You will get an excellent feel for the rifle and how it operates.

While you may think that the ideal approach will be to just buy a new AR-15 in .22 LR, the truth is that you may be better served by getting a conversion kit to quickly and efficiently convert your AR-15 from its existing caliber into .22 LR. Conversion kits are usually much cheaper than buying an entirely new rifle, and they are not permanent either. You can convert between calibers in a matter of seconds if you become efficient at it.

In the next section, we’ll talk about the two primary types of conversion kits on the market today.

What Are The Different Types of AR-15 .22 Conversion Kits?

There are many different kinds of .22 LR conversion kits that are available on the market, but most of them are based off the same basic design. This design is that the existing reciprocating blowback bolt is replaced with a new blowback bolt that is optimized for the .22 LR rifle.

However, this design can come in two different primary forms: the Atchisson-style conversion kit (which is the most common) and the dedicated .22 LR upper receiver.

If you are looking to keep your existing upper receiver and are looking for the cheapest conversion option possible while maintaining quality, then the Atchisson-style conversion kit is what you are after. This is basically a drop-in .223 (or other caliber) to .22 LR adapter that is designed to fit into your existing upper receiver.

The Atchisson-style conversion kit is named after Maxwell Atchisson, who developed the kit that bears his name back in the 1970s. The design was later improved upon by Jonathon Arthur Ciener.

A typically Atchisson conversion kit consists of a bolt group assembly and a magazine chambered for .22 LR but that will also work in standard AR-15 magazine wells. Field strip your AR-15, remove the existing bolt group assembly (bolt and bolt carrier), put the rifle back together, and then use the .22 optimized magazine with this.

This method does not permanently alter your weapon, and no tools or gunsmithing services should be required as well. The magazines in an Atchisson kit are of the same size as a centerfire magazine, but have a follower and spring designed to accommodate the much smaller .22 cartridges.

However, you should take note that most Atchisson .22 magazines will not hold the bolt of the AR-15 open when the magazine runs dry. Instead, you’ll pull the trigger only to hear a CLICK to realize that the magazine has run empty (assuming that you’re not counting rounds).

The alternative to the Atchisson is to go with a dedicated upper receiver chambered in .22 LR. A dedicated upper receiver in .22 LR can also be installed without the aid of tools or a gunsmith as well. You literally just have to replace the uppers with your existing lower, use a .22 LR magazine similar or identical to what is included in an Atchisson design kit, and you’re set to go.

A dedicated .22 LR kit will be much more expensive than an Atchisson-style kit, and this is what keeps many people at bay from purchasing them. But on the flip side, the accuracy and reliability out of a dedicated upper are usually a bit superior. That’s because the AR-15 barrel, bolt assembly, and barrel collar are optimized to work with the lighter .22 projectile.

Just take note that a dedicated .22 upper can be very expensive and sometimes will cost well over twice what you would pay for an Atchisson conversion kit. At that point, it may just make more sense to buy an entirely new .22 LR AR-15.

Also take note that regardless of which conversion kit type you go with, a break-in period is usually necessary. You’ll need to fire a couple hundred rounds out of your rifle in order to confirm that it functions properly. Furthermore, many .22 LR conversion magazines that ship with conversion kits often have tough springs that can be difficult to load rounds into at first. But the more rounds you load into them, the more they should loosen up.

Buyer’s Guide For The Best AR-15 .22 Conversion

These are the most important factors to consider when looking for a new .22 LR conversion kit for your AR-15:


First and foremost, you need to take price into consideration. After all, the whole reason to go with a conversion kit rather than purchasing an entirely new .22 LR rifle is to save money. As a golden rule, you should expect to pay around $200 to $250 for a conversion in .22 LR that comes with at least one magazine. If you pay anything significantly higher than this, you may as well just buy an entirely new rifle.

Drop-In Design

Your conversion kit should be as easy to replace as possible. Simply break open your AR-15, remove the existing bolt and carrier, and then install the new .22 LR optimized kit. Swap out the magazines, and you should be good to go. It shouldn’t take more than a few minutes to convert your AR-15, and you certainly should not need any extra tools or the aid of a gunsmith.

A Good Magazine

Last but not least, make sure that your kit comes with a good magazine that can reliably feed .22 LR ammunition. The best conversion kits will come with an included magazine so you can begin firing .22 LR ammunition right out of the box. If it’s legal, your magazine should ideally be capable of holding around 25-rounds of .22 LR ammunition.

Take note that just because your conversion kit comes with a magazine doesn’t mean that you should not stock up on additional magazines that you can buy separately. Remember, you can never have too many magazines.

Looking for more buying guides on parts? We also covered the best AR-15 pistol lowers and how to pick a good featureless grip.

The Best AR-15 .22 Conversion Kits For 2020

Now that we’ve covered why you need to convert your AR-15 to .22 LR and the top qualities to look for in a conversion kit, here are our top three choices for a conversion kit for an AR-15 in 2020:

CMMG AR-15 .22 LR Bravo Conversion Kit

CMMG AR-15 .22 LR Bravo Conversion Kit

The CMMG AR-15 ,22 LR Bravo Conversion Kit is a solid choice to convert your AR-15 from 5.56 to .22 LR. It’s capable of loading 25 rounds of .22 LR ammunition with the provided magazines and allows you to convert the bolt and the bolt carrier to .22 LR in order to create a fully functioning .22 rifle. Take note that the spring in the magazine is a little stiff, and it therefore can be a little difficult to fit individual rounds into the mag.

This kit is an Atchission-derivsed type kit. It’s also a one-piece drop-in unit to make the conversion process as simple as possible. If you know how the internals of an AR-15 work and how to field strip one, you can have this kit installed in a number of minutes. The Bravo kit will replace the standard 5.56 bolt and the bolt carrier with a new .22 LR bolt that has new recoil springs optimized for the .22 LR as well.

All in all, if you’re looking for a relatively inexpensive and fast way to convert your AR-15 from 5.56 into .22 LR, this is one of the best conversion kits you can go with. You’ll have a new bolt and bolt carrier installed in your AR-15 along with a new magazine, and you’ll be ready to send .22 LR rounds downrange.

See on Brownells

  • Comprised of very durable parts
  • Ideal for .22 LR rounds from 69 to 75 grains
  • Impact proof
  • Designed for direct gas impingement guns
  • Can be difficult to load the individual rounds into the magazine
  • Does not work with piston ARs

CMMG AR MK57 Conversion Kit with 3 Magazines

CMMG AR MK57 Conversion Kit with 3 Magazines

If you want an AR-15 .22 LR conversion kit that is incredibly easy to install, you’ll want to take a look at the CCMG AR MK57 Conversion Kit. As the name suggests, this kit is designed to convert AR-15s that are chambered in the 5.7x28mm round.

This kit has a drop-in conversion design that can be installed in a matter of seconds, so long as you are using an AR-15 built to mil-spec configurations. Three black-colored 25 round magazines are shipped with this conversion kit.

Overall, the MK27 Conversion Kit is one of the best conversion kits for converting an AR-15 chambered in 5.7x28mm. This kit has a drop-in design so it can be installed in a matter of seconds, and as an added bonus, comes with three extra magazines in one package.

See on Brownells

  • Very easy to install
  • Compatible with any mil-spec AR-15 chambered for 5.7x28mm
  • Comes with 3 25-round magazines
  • Not designed to convert 5.56x45mm NATO AR-15s

CMMG Echo SS Arc Kit w/ 25 Round Magazine

CMMG Echo SS Arc Kit with 25 Round Magazine

The CMMG Echo SS Arc Kit is designed to install as easily as possible into your AR-15. This kit is designed to replace the bolt and carrier with replacements that are optimized for the .22 LR round. Many users have reported that this conversion kit works the best with 36 grain .22 LR ammunition.

Something else you will notice about this kit is the steel gray magazine it comes with; most magazines that ship with .22 LR conversion kits are usually black colored. While matte gray may not be the most appealing, this magazine can fit 25 rounds of .22 LR ammunition. This magazine is also easy to load, unlike several other conversion kits where a fair amount of pressure may be required to fit the rounds in.

All in all, the CMMG Echo is a solid pick for a conversion kit. It’s easy to load, comes with a drop-in bolt and carrier, and also comes with the addition of a forward assist adapter. This is the kind of carrier group that will easily last you for a lifetime.

See on Palmetto State Armory

  • Compatible with both 5.56 and .22 LR rounds
  • Very easy to convert
  • Easy to load
  • Comes with a forward assist adapter
  • Gray colored magazine is not the most appealing

Wrap Up

If you want to get an AR-15 in .22 LR, a cheaper alternative can be to just purchase a conversion kit rather than get an entirely new rifle. Any one of the three conversion kits that we have discussed here will be a good option for you, and for an alternative option, you can buy any other conversion kit that meets the criteria that we outlined above as well.

1 comment
  1. I just ordered the cmmg bravo kit from classic firearms for Christmas.
    Gunmagwarehouse also sells the 22 conversion mags on their website for around $20.
    Haven’t received it yet, but am excited for its arrival.

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