Brownells’ AR-15 .22 LR Conversion Kit

SayUncle has reviewed the Brownells’ AR-15 .22 LR Conversion Kit for Shooting Illustrated. It is well worth reading.

Brownells’ .22 Bolt

The bolt design, which is mostly the same across all the .22LR AR-15 kits, is ingenious. I would never have thought up that concept.

What is appealing about Brownells’ kit is that the magazines are similar in size to the AR-15 magazine. The other kits I have seen use magazines which are small and skinny.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • D

    I have the CMMG kit that uses a full sized .22 LR AR mag these kits work well but there are a few things that you have to know (1) they MUST be kept well lubed, (2) use only good High Vel. ammo not the cheap stuff, and (3) they will not eject an unfired cartage easily.

  • If you like those magazines check out CMMG for even better looking magazines

  • Ernunnos

    These are Black Dog magazines, made for Brownells. (I actually got some Brownells-marked magazines direct from BDM.) They work with most AR .22 conversion kits, including those that originally came with “skinny” magazines, as well as the Kel-Tec PLR22 and SIG 522.

  • The “skinny” mags are a throwback to the original Ceiner kits from years ago…they were very reliable but we only ever had the one that came with the kit because the damned things were very pricey. The Black Dog Machine mags work AWESOME in the Ceiner-style conversion kits (Spikes, Brownell’s, CMMG, Tactical Solutions, etc.) and they also have a 50-round drum that works great.

    They were showing prototypes of their 3rd Generation magazine with steel feed lips at SHOT which hasn’t been released yet…it was blogged here with pics by myself way back then.

    Apparently they are also making a billet aluminum mag now also but I haven’t used one yet. One of the hosts of our upcoming machinegun shoot does beta testing for them…maybe Rachel was a doll and sent him one so I can play with it at the end of August!

  • “gunner”

    that looks like a useful accessory for my daughter’s ar-15, she’s got all the g.i. kit, bayonet, blank adaptor, butt well cleaning gear and web sling, along with the tm and fm manuals and comic book, but this would make shooting the rifle a lot less expensive.

  • jdun1911

    The Brownell kits are Ceiner. Ceiner bought the patent from Maxwell Atchisson and made a large amount of money out of it. I remember a time where he was the only player in town. Customers that wanted his conversion kit had to wait for months. Since the patent is gone other companies move into his turf.

    The owner of Black Dog Machine is swimming in money. For a long time he was the only one that made AR15 type magazine for Ceiner and other conversion kits. These magazine cost over $20.

    Black Dog Machine magazine are very very reliable. All my BGM magazines have well over 10k each and still going strong. The problem I have is they are not durable enough to be drop onto the ground. I try to convince Magpul and Lancer to produce a durable .22lr magazine in the past.

    I am looking forward to CMMG bolt hold open AND the ability to drop the bolt down with the bolt catch. This will make the Ceiner conversion kit work like a standard AR15. Everyone is excited about it. I know I am.

  • Ivan

    Errr… so, what thing have no egector??? And for convert your AR15 you just need to replace boltkit? Without changing the barrel and gas key?

  • Pete Sheppard

    Black Dog also makes 15 and 10 round AR-style mags, if one is interested (or required).

  • Bill

    I’ve had a Ciener kit for several years that I got from Midway USA. It’s interesting that Brownells is putting their brand on it The weak link so far is the firing pin. Mine broke recently and it’s a $11 part.

    As others have said, this design has been around a while and if you look at CMMG’s and Spike’s, it is very similar. It also may have to do with the patent lapsing.

    I agree that Black Dog Machine is rolling in it. That outfit was the only game in town for a long time but his design is proven and reliable. More power to American innovation!

  • Tam

    Be aware that rimfire conversion kits in the AR are capable of firing quite some distance out of battery.

    Always wear eye and ear protection!

  • TimE

    My question is the twist rate… 1-7, 1-9 vs. 1-16. Any impact on accuracy?

  • jdun1911


    All that needs to be replace is your BCG. 10 second install. That’s it. A 1:9 twist or slower is prefer. 1:7 twist will work but at longer range it might keyhole. Most barrel in the last 10 or so years will have twist marking on it.

    I have the older BDM magazines that won’t hold the bolt open on the last round. They introduce magazine bolt open followers two or three years ago. They also sell the followers separately. Problem is that the follower won’t engage the bolt catch. It just open the bolt on the last round without the use of the bolt catch. In other worlds, if you take the magazine out the bolt will drop.

    The CMMG drop in mod that is coming out later this year will engage the bolt catch. Good stuff.

  • jdun1911


    Yes the twist rate will have an impact on accuracy. 1:16 is the ideal twist rate.

  • jamso1911

    Does anybody have experience with the CMMG dedicated AR-15 .22LR upper? It appears that CMMG has the only device that allows the bolt catch to operate as it normally does on an ar-15, so I was thinking it may work best with a CMMG upper, but I suppose that it may work with dedicated uppers from other manufacturers. Does anyone have any insight on this?

  • The Brownells (actually CMMG) conversions are nifty. However even better is to pick up a CMMG dedicated .22RF barrel and adapter and build a dedicated .22 RF upper.

    See for pictures (about half way down the page).

    Some hints for reliability.

    1) Debur and polish all bearing surfaces of the conversion and keep lubricated.

    2) As previously mentioned use plated bullet HV ammo. CMMG recommends the 36 gr HVHP loads but try several and see what works best for you.

    3) If you have the typical square notched AR hammer consider replacing your hammer with the rounded top “GI” style hammer for better reliability.

    4) CMMG offers a special .22RF charging handle that is filled in to prevent RF rounds from getting stuck in the handle.

    You can also modify a charging handle with an epoxy filler.

    My nit has digested close to 500 rds with only on stoppage.