The Most Comprehensive Review of the CMMG 22lr Conversion Kit

There are many reviews of the CMMG 22 long rifle conversion kit on KZbin, but I've tried to make the most comprehensive one on the topic. It's longer, but I think worth it.
0:00 Intro
2:12 Chronograph
5:02 Accuracy
11:21 Reliability
18:13 Design and Disassembly
23:53 Concluding Thoughts
Email: [e-mail]
Utreon: utreon.com/c/8mmmauserman (Please be patient; I'm still getting this running)
Venmo: @Official_8MM ($3 and your address for an 8mm Mauser Man sticker)
Outro Music: PT109 by Jimmy Dean

[@exquisitearangement]

Over the course of the last three years, i have put between 4 and 5k rounds through one of these in three different uppers. The 1/7 twist barrels were much less accurate past 25 yards than the 1/9 that I subsequently prefer to use. The worst issue i have had, after 500+ rounds, the gas block and the tube get completely filled with filthy .22 residue that gets blown out by standard 223 ammo, filling the bolt carrier, and welding the gass rings to the bolt. After this happens, you might need to replace the gas rings, as they will likely break during removal for cleaning. This may not be an issue for all uppers, and might depend on the location of the gas port either in a land or grove of the rifling. It has happened to me twice, and everyone should be aware of this possibility.

[@8mmmauserman]

Out of curiosity, what brand uppers were you using?

[@exquisitearangement]

@@8mmmauserman gov profile colt surplus 14.5" 1/7, no name 10.5" 1/7, and a Rogio 14.5 1/9 that was more accurate. I ran about 100 through a faxon 18" gunner profile with absolute garbage accuracy.

[@8mmmauserman]

Interesting… thanks for sharing your results.

[@DogeMcLovin]

Awesome write up! Based off your comment and what others say, I think I will clear the gas tube at around every 200 rounds and do a cleaning after each range trip. Also, how have your groupings been past 25 yards with your 1/9? Sounds like my kind of fun!

[@MegaBait1616]

I bought an M&P AR-22 rifle for $ 329.00 plus tax n B/C.... Think was a good deal......be well.

[@Xoarkitty]

I took a co-worker to the range after he told me he though the "AR" in AR-15 meant "assault rifle." I showed him how to safely operate and handle the rifle, how to load the magazine. Then sent to the 25 yard line to set up the target. While he did this I swapped out the standard bolt for this, CMMG conversion bolt, loaded and put on the safety. When he returned I showed him again how to turn off the safety and how to should the rifle, where to put the red dot. I then stood behind him with my hand pushing on his shoulder, which caused him some concern regarding the recoil. After he fired the first shot the look on his face was priceless. Take your anti gun friends to range and let them shoot your scary black rifle. It's fun.

[@8mmmauserman]

I love taking friends to the range. It's seriously the best

[@Santaheckler]

Brilliantly done! 😆👍

[@unscrupulousrapscallion9426]

I bought one of these several years ago (3-5 yrs?) .. the short barrel on the conversion kit split and it stopped cycling properly .. I sent an email to CMMG and they had a replacement chamber unit in the mail the next day .. no issues since .. another product that makes this even more fun is the McFadden Industries Lightnin' Grip Loader .. they're quite affordable and make loading those 25 round .22LR mags almost as much fun as emptying 'em .. thanks for the video

[@8mmmauserman]

I’ll have to check it out. Thanks!

[@imthatguy1878]

Love the Paul Harrell chrono turn as you say the numbers

[@rammhansen37]

Yes! A very thorough review. Thank you for your work. It’s very helpful for those of us who are starting fresh, not knowing anything about it .

[@8mmmauserman]

Glad I could help. I’ve always wondered the reproductions of shooting thousands and thousands of rounds. I obviously haven’t done that yet, but I got my fiance an upper with this kit, so I’ll be doing that in a few years probably

[@jasonsierchio1167]

Well done video. Appreciate your time sir.

[@wsidepac455]

Straight to the point Clear affirmative

[@g.barrett8410]

Outstanding video. This was exactly the detailed info I was looking for about the CMMG .22lr conversion kit.

[@8mmmauserman]

Glad to help! I simply answered the questions that I wanted to know.

[@glabdo5000]

This sure did help tilt my purchase decision for one of these. Thank you, 8mm Mauser Man!

[@8mmmauserman]

Glad I could help!

[@znklnkrt2944]

This is a solid well detailed video. Thank you.

[@8mmmauserman]

Glad it was helpful!

[@charlesgillette2925]

Very much enjoyed this video, Well done and explained.

[@8mmmauserman]

Thanks for the comment!

[@patrickpewpew9782]

Good to know. Just picked up one of these kits. I do get a lot of herters bulk for my p17, 10/22, savage 64 and Mark ii so good to know it works well

[@REMYSCH]

Great video

[@whizwit215]

Love mine! Runs everything I feed into it. Your findings are about the same as mine. Winchester white box runs too. Anything high velocity with the occasional hiccups as you showed. Cci runs near flawlessly, of course. Great vid! Long runtime too, dig it!!

[@8mmmauserman]

Thanks for the comment!

[@Santaheckler]

Nice review! 😎👍

[@8mmmauserman]

Thanks! 👍

[@drysori]

Bore buddy makes a lot of addons and improvement parts for the CMMG conversion kit.

[@user-xx2es4ip2k]

Great video. I have a few of the CMMG conversion kits and have found they work very reliably if you DO NOT use the new style CMMG mags; instead stick with the old-style mags that you show in your video or use Blackdog Machine Steel lip mags. I have also found the CCI 36grn Mini Mags work best for ammo.

[@JNOSNOW]

I wasn't aware of the new mags until looking very recently. I have found that I had surprisingly good luck with my old mags and kit. I barely use it relatively though since getting all of the suppressors so now I'm building a 4.5" dedicated and throwing it on its own lower

[@Santaheckler]

I’ve been using the new style CMMG mags and haven’t had any issues at all after over 500 rounds. I use Federal 40g auto match mostly. I have a S&W mag and it gives me issues once in awhile, like it doesn’t seat right sometimes. But that could be a lower issue 🤷‍♂️. The .22 mags wiggle so you can’t hold them or lean on them whatsoever while shooting.

[@froggerjohn427]

I have 3 of the gen 2 mags and they work 100% reliably. I just oiled the rails straight out of the package and after 1200ish rounds of aguila standard velocity the 4 failures I’ve had were from pivoting on the mags

[@jaredhighlands4604]

I used to have the savage model 62 wood stock just sold it since it was a decade almost old and never use it... now seeing it in video i kinda miss it

[@8mmmauserman]

There are a number of design quirks I'm not a fan of, but... it is cool

[@benkanobe7500]

I have four of these kits purchased over many years. Two of the kits were purchased in the last 3 years. They have a brass-colored collar around the the feed ramp/chamber sleeve that has a retaining clip. I used a micrometer and it is just a little smaller than the same section on my earlier kits. It is there to be less aggressive on the locking lugs when it engages the chamber? It appears to be a design improvement, but my old ones work perfect with quality HV ammo. Just thought maybe you knew. Thanks!

[@8mmmauserman]

I’m not sure, but thanks for the comment. I have wondered if you would run into any issues with the bolt causing the whole kit to rock back and forth impacting the barrel extension thousands of times.

[@joemorganeatmyshortschannel]

My only issue with that is potentially carbon fouling so I'd keep spare gas tube

[@8mmmauserman]

I haven’t shot thousands of rounds yet, but I haven’t had too big of an issue there yet. I’d say as long as you regularly shoot 5.56 through the upper as well, it shouldn’t be a massive issue

[@laremm]

@@8mmmauserman I have a piston instead of DI. Is there a huge issue?

[@8mmmauserman]

@@laremm Good question. I don't think there would be as long as the chamber and bolt dimensions are the same, but I'm not sure.

[@ungratefulpeasant8085]

I shoot a couple 5.56 rounds every three hundred or so .22lr's. No problems so far. You could always use a pipe cleaner for the gas tube every now and again or keep a spare gas tube.

[@jasonsierchio1167]

Have you tried the CCI AR Tactical 22LR rounds?

[@8mmmauserman]

No I haven’t, but if they’re high quality, I’m sure they’d work well.

[@tomjones5418]

Ok so I have no more questions on that

[@8mmmauserman]

Glad I could help

[@spoonskill7080]

Great video. Appreciate all the work you put in. One issue; your Ar-15 shooting 5.56/.223, is over-gassed. Your spent cartridges are ejecting to the one o'clock position. Try a heavier buffer, and make sure your gas tube is the correct length for your barrel. You want to eject between the 3 o'clock and 4 o'clock positions. Great job!

[@8mmmauserman]

Are you referring to the 20" or 16"? The 16" is a carbine length, so not ideal...

[@spoonskill7080]

@8mmmauserman The 16 inch. Start with an H2 buffer and work up (H3, H4..) until you get the correct ejection pattern. It must be a buffer weight issue as your 16-inch has the correct carbine length gas tube. Your bolt seems to be traveling faster than it needs, increasing felt recoil.

[@jiminysnicket86]

Military rifles eject at about the 1 o'clock position, js

[@bigtrev761]

🇦🇺😎👍Hey Big Bad Brother John …that looks like snow on the ground 🤔💭I thought it was heating up over there atm. It’s freezing 🥶 down here atm…yep looks like snow to me…if you were shooting a gun next to the road down here , someone would call the police. Out of sight , out of mind. Heaps of attention seekers down here…..interesting video mate

[@8mmmauserman]

It’s hot now, but I’ve had this for a while to give it a comprehensive review.

[@bigtrev761]

@@8mmmauserman Go Big John🏁

[@BoreBuddy]

Now you just need some of our upgrades for the kit! Or if you want to try out a 22lr AR upper that uses that same style bolt, let us know.

[@8mmmauserman]

I'm interested. Send an email to [e-mail]

[@incredible3214]

These are project conversion kits. Look up all of the videos that deal with failures. I bought one and threw it in the trash. But, I did buy their dedicated .22lr upper and it runs decently. I prefer my BCA dedicated. 22lr upper.

[@8mmmauserman]

This has worked very well and reliable for me and countless others. What do you mean "project conversion kits?"

[@incredible3214]

@8mmmauserman I mean that for many others it requires alot of tweaking before they work reliably. I bought CMMG's dedicated .22lr full upper and it's OK. But, the kit they sent me was garbage.

[@8mmmauserman]

@@incredible3214 Oh, I see. From what I've seen that's a pretty rare result, but it has been through a few iterations

[@vicv7075]

Honestly .22lr rifles can be had very cheap so I just went that route instead of buying this kit and hoping it worked out.

[@8mmmauserman]

I can recommend that to, but the advantage of this can be to train directly with your AR

[@ilikegearsofwar3]

Ar looks cooler, quick conversion, no ffl needed win win

[@mfrfpv9079]

its bad to dry fire this kit?

[@8mmmauserman]

I wouldn't. Generally it's recommended not to dryfire rim fire, but if you wanted to, you could put the 5.56 bolt back in I guess

[@mfrfpv9079]

@8mmmauserman I have JMT a drop in trigger will it work with the cmmg 22lr kit

[@8mmmauserman]

I don’t know. The only way to know is to try it. I think you should be ok if you use a higher velocity ammo, but also this kit gets your gun dirty, and I know drop in triggers can be impacted by that a bit more.

[@mfrfpv9079]

@@8mmmauserman i took the pin out jik

[@WEthePEOPLE_888]

Ogla eht rof tnemmoc

[@KyleKalevra]

It’s a good video, but an AR15 with a carry handle is not an M16. An M16 (variant) is select fire, either 3 round burst or fully automatic. That is not an M16 or any variant of it.

[@8mmmauserman]

Sometimes words have colloquial meanings. If I say "my M16a1..." everyone in the audience knows that I am referring to the gun in my hands that is a semi-automatic rifle that closely resembles the M16a1. I say this because "My AR-15 that closely resembles an M16a1 because it was built on a parts kit with a replaced lower receiver and barrel" is too long to say every time.

[@ranchlife8128]

He said "type rifle". Pay attention next time.

[@KyleKalevra]

@@ranchlife8128 It’s difficult to pay attention to someone who doesn’t know what they’re talking about ramble on about said subject. I’ll keep it simple. All AR15s are M16 style rifles because they are almost exactly the same firearm, aside from the select fire. A carry handle does NOT make it MORE M16 like, the ability to shoot full auto or 3 round bursts does. What he’s holding is an AR, not an M16/M4. It’s no more like an M16 than any other AR you can buy or make yourself.

[@ranchlife8128]

@@KyleKalevra You're preaching to the choir but what you're still not doing is paying attention. He said "type rifle" and shook his head indicating "you know what I mean" and then further explained to you what he meant. I can't make it any simpler than that. Relax and enjoy one of the most comprehensive reviews you'll find on KZbin about this product. If you want to further argue nonsense good luck, because I won't.

[@KyleKalevra]

@@ranchlife8128 Sorry, not sorry. But calling it an M16 type, and giving a look, is perpetuating that nonsense. Call it what it is so the audience, who is supposedly learning from this video, gets the correct information, not some insinuation of what you meant.

[@john-xu7kt]

remington thunderbolts run great. a bit dirty

[@8mmmauserman]

Good to know!