.22 LR - CMMG conversion kit or dedicated BCA Upper?

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Synack42

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Apr 13, 2022
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I have a spare lower and red dot. For target shooting at 50/100 would you prefer the CMMG conversion or a dedicated Bear Creek upper?

I've heard not so great things about .22 LR accuracy in a 1:7 twist barrel. The BCA upper is 1:16 and no gas system to worry about fouling up.

I do have another BCA upper in 5.56 and yea, the fit and finish isn't great -- had to tighten the handguard and whatnot... I'm alright with that little stuff for a plinker as long as it's accurate and the bolt doesn't fall apart.

Curious as to what the consensus is... Thanks
 
I have two CMMG 22LR conversion kits and BCA dedicated 22LR 16" upper.

I have used CMMG conversion kits on 16"/18"/20" 5.56/.223 Wylde uppers with 1:9/1:8/1:7 twist rate barrels. Due to slightly larger bore and faster twist rate, I have used only copper plated ammunition (No Lead RN due to concern for leading of bore) and accuracy is definitely not on par with .22LR dedicated rifles and barreled upper. While 10/22 and T/CR22 with factory 1:16 twist barrels produced sub 1" groups at 50 yards with select ammunition, groups from CMMG conversion kits were larger and worse if fouling build up is not addressed.

Another thing with CMMG kit is fouling build up of conversion bolt and reliability improves with more frequent cleaning of every several hundred rounds (As long as I kept the CMMG bolt clean, I experienced reliability with all different copper plated ammunition). But for close range, especially fast point shooting drills at multiple targets and minute-of-soda can plinking at 30-50 yards using same manual of arms/trigger for much cheaper cost training, CMMG conversion kit is well suited. I use CMMG (Plastic feed lips) and Black Dog (Metal feed lips) magazines with reliable feeding.

BCA dedicated 16" 22LR upper with heavy barrel uses 1:16 twist rate with bore size suitable for .22LR ammunition - https://www.bearcreekarsenal.com/22...el-1-16-twist-15-mlok-scg2-nrail-branded.html

While not as accurate as .22LR rifles, BCA 22LR upper has been reliable with various ammunition tested with no concern for Lead RN use due to .22LR sized bore and slower 1:16 twist rate barrel. With same manual of arms/trigger for close range, fast point shooting drills and allow minute-of-soda can plinking at longer 75-100 yards. BCA 22LR upper has been reliable with both CMMG and Black Dog AR22 magazines.
 
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My cmmg conversion has never ran a full mag, ever. I have over 500 rounds of 6 different brands/loads of ammo through it. I've tried it on a m&p with a carbine length gas system, a ruger mpr and a psa with full length gas systems, and it constantly jams no matter how clean and well lubed it is. The pic shows how it always jams. Screenshot_20240509-183915_Gallery.jpg
 
Walkalong said:
My wife has a dedicated CMMG upper, it’s reliable and shoots pretty well.

I always advise for a dedicated.22 upper if funds allow
Click to expand...
Yes, I agree that dedicated 22LR upper is better in reliability and accuracy with less cleaning needs than 22LR conversion.

MrShooter said:
My cmmg conversion has never ran a full mag, ever ... I've tried it on a m&p with a carbine length gas system, a ruger mpr and a psa with full length gas systems

it constantly jams no matter how clean and well lubed it is. it always jams.
Click to expand...
CMMG conversion turns gas operated AR to blowback action which relies on weight of bolt/buffer and spring rate to reliably cycle.

CMMG conversion has internal bolt and spring that actually moves within the "bolt carrier group" (Receiver frame and chamber adapter assembly) so if spent case is not properly ejecting to cause stovepipes (But fully extracting), you may have issues with internal bolt not moving back far/fast enough to completely eject the spent case and/or issues with extractor.

22BA492__89513.1714577346.386.513.jpg


If thorough cleaning and lubrication to ensure proper cycling of internal bolt does not reliably eject spent cases, you may need to contact Customer Service (Select "Tech Support" under "Category) - https://cmmg.com/contact

I have used my CMMG conversion bolts with 5.56 NATO and .223 Wylde chamber uppers with reliability but used only copper plated HV 22LR as indicated by CMMG website (But if conversion bolt gets dirty after several hundred rounds, it become less reliable until cleaned) - https://cmmg.com/22lr-ar-conversion-kit-bravo-w-3-magazines-blk

Just swap this drop in conversion with the bolt carrier group from your 5.56/.223 chambered rifle and you will be ready to shoot .22LR ... For best performance use a round style hammer as notched hammers can cause function issues and 36 grain plated nose bullets have proven to be the best choice for function.​
​
**Since .223 WYLDE is NOT a mil-spec chamber, we cannot guarantee fit or function with our 22LR conversion kits**​
 
maxxhavoc said:
I went with one of these kits on a standard upper:

Has been very reliable. I haven't given it enough range time to do an accuracy test yet.
Click to expand...
With 1:16 twist rate barrel, should produce better accuracy than conversion for 1:7/1:8/1:9 barrels.
 
foxmeadow said:
I consider a .22LR conversion kit to be a training tool for weapon manipulation. If the accuracy isn't terribly great, oh, well. My CMMG kit serves me well, as 6" plates at 50 yds. aren't a problem.

If you really need the accuracy, get a dedicated upper.

.22LR ammo is dirty, dirty, dirty. You need to clean up after it..
Click to expand...

^^
This.

IF 50/100 yds is your goal, depending on the size of your TGTs, you're not going to be satisfied with a .22LR conversion in a .223 upper.

I've used a conversion unit, a S&W M&P15-22 for training/practice with AR15s and finally went with a 9mm PCC as the .22LR just wasn't close enough in the recoil dept.
 
I run a CMMG conversion for closer speed drills. Precision accuracy isn't needed, and not having to worry about "kitting out" a second upper to match my go-to upper is nice.

Runs well in my 16 inch FN chrome lined middy upper, and a Franken 7 inch "breifcase" gun. With or without a can. I've only run CCI SV. I have other stuff on hand to try though.
 
This video will provide you with some good food for thought on this subject:

www.youtube.com

.22lr in .223 (CMMG Ciener set): 1:16, 1:12, 1:9, 1:8 twist rates.

Join us on The App! https://www.weaponsandwar.tv/Bloke thinks that the .22 rimfire Ciener type chamber insert small bore conversion systems for .223 Remingto...
www.youtube.com www.youtube.com

I have a CMMG conversion that works very reliably with my Fightlite build using Black Dog Machine 10-round magazines. Accuracy is all that I could want at the distances I shoot, but I'm not especially demanding and YMMV.

HTSightsPA1x.jpg

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I used a CMMG conversion kit in my AR for a time. No problems at all except accuracy wasn't great. Not terrible though and good enough for casual plinking. Then I bought a BCA upper. It won't win any bench rest matches but it certainly beats the conversion in accuracy. If not for the weight it would be perfectly adequate for a small game rifle. I have no interest in doing drills and am no longer capable of it if I did.
 
doubleh said:
I have no interest in doing drills and am no longer capable of it if I did.
Click to expand...
I do close range fast point shooting drills at multiple targets (2 shots per target) and both CMMG conversion and BCA dedicated upper are great for these shooting drills due to much lower cost for very high volume shooting.

Have you considered trying cadence shooting? You can do cadence shooting practice while sitting down at the bench.

Fast cadence shooting demonstration of AR-15 from 2 to 5 shots with control and accuracy at 5:23 minute of video below (Yes, this is SEMI-AUTO fire and I usually practice with 2-3 round cadence
youtu.be

How to shoot faster (With Mojo)

LAS CONCEALMENT - Code "Garand Thumb" for 10% offhttps://lasconcealment.comACRE GOLDhttp://lddy.no/ggyvLeviathan Group (Use code GT10 at checkout)https://www...
youtu.be youtu.be
 
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Thanks everyone -- Will probably go with the dedicated 1:16 upper to keep my sanity when going out to 100 with it.
 
We used the M261 conversion kits quite a bit when I was in the Army. We qualified at 25 meters when using the conversion kits. The M16A1 was always more accurate with its 1-12 twist when compared to the M16A2 with the 1-7 twist. Neither will be as accurate as a dedicated 22lr barrel. I run a 1-16 and 1-12 twist heavy 22lr barrels on my dedicated uppers. The Ma16A1 still won't be as accurate as a dedicated 22lr barrel with a 1-12 twist.
 
I have the CMMG kit, I prefer the kit to a dedicated upper.
My kit is pretty reliable but throws a random stovepipe every 50 rounds or so. Still reliable enough for drills though.
The kit is excellent for getting a rough zero of new optics,
it is excellent for keeping you familiar with your defensive rifle as it is configured.
Accuracy isn't great, but I have dedicated .22lr rifles for accuracy.
 
I was just looking into this myself the past few days. Anyone have any experience with the BCA 10.5" uppers? Thinking that it would make a nice trainer for my MK18 clone and possibly a decent backpacking squirrel rifle.
 
Conversion kit always "feels" like it ought toe be better/simpler.
But, there's a hiccup, it will be in the replacement bolt group, or in the magazines (especially in the magazines).
And, those hiccups will suck the "fun" out of having the 22lr capability.

I've used both, and prefer a dedicated 2LR, whether upper only or upper and lower, both. (Lowers without uppers will "breed" lowers--fair warning.)
The above (and a sweet sale price due to the Grand Opening Sale) is how I have an S&W M&P 15-22. Is it ideal? Kinda. Mags are proprietary and not cheap. But, reliable and came with a cheap dot sight on it. And is a heck of a lot of fun.
Starboard Side.jpg
Does it 'match' anything in the safe? Not in the slightest. But, it's fun to shoot and will happily digest cheap 22lr ammo (if not as tightly as Aguila HV).

Your Mileage May Vary
 
Dedicated upper.

If you don't mind the weight (BCA everything is cheap so heavy). Otherwise, M&P 15-22 rifle would be what I would buy...because I did lol
 
I found out right off the bat that the CMMG magazines are hard to load. Some research led me to a .22LR reloading system that makes it easy. the Lightnin'Grip Loader, from McFadden machine, offers adapters to fit many .22s It loads the CMMG mags, as well as AR15-22, mags like Ruger Mark 4, TX22 and a host of others. www.mcfaddenmachine.com It will load a 25 rd. CMMG mag in under 15 seconds...
 
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maxxhavoc said:
I went with one of these kits on a standard upper ... I haven't given it enough range time to do an accuracy test yet.
Click to expand...
zdc1775 said:
I was just looking into this myself the past few days. Anyone have any experience with the BCA 10.5" uppers?
Click to expand...
Will plan a three-way 50 yard group comparison on next range trip for CMMG conversion bolt in 1:8 AR barrel vs BCA dedicated upper in 1:16 vs 10/22 or T/CR22 in 1:16 comparison - https://www.thehighroad.org/index.p...ar-upper-50-yard-groups.932322/#post-12943971

silicosys4 said:
I have the CMMG kit, I prefer the kit to a dedicated upper.
My kit is pretty reliable but throws a random stovepipe every 50 rounds or so.
Click to expand...
Will also report on feeding/reliability of CMMG/Black Dog AR22 magazines and extraction/ejection that some THR members have posted about BCA 22LR upper in years past.

Any particular brands/weights/lots of ammunition you want me to test? (I have 52 brands/weights/lots and planned on doing Aguila 40 gr CPRN and Federal AutoMatch to start)
 
I bought one of the PSA 1:16 uppers a couple years ago and finally started using it and I'm very impressed. I used a standard PSA lower converted with the redi mag adapter and the thing just runs so far, with great accuracy results from ammo it likes, the S&W .22 Mags also fit in solidly, it's just a really nice package.

Unfortunately, they are out of stock, but given how well these perform, I'd look for a PSA .22LR upper when they come back in stock or possibly consider picking up a S&W .22LR or other quality brand.

https://www.redi-mag.com/product/better-mag-s-22-rimfire-magazine-adaptor/

https://palmettostatearmory.com/psa-16-22-lr-1-16-nitride-13-5-lightweight-m-lok-upper-with-bcg-ch-516446934.html
 
LiveLife said:
Will plan a three-way 50 yard group comparison on next range trip for CMMG conversion bolt in 1:8 AR barrel vs BCA dedicated upper in 1:16 vs 10/22 or T/CR22 in 1:16 comparison - https://www.thehighroad.org/index.p...ar-upper-50-yard-groups.932322/#post-12943971
Click to expand...

I took the CMMG dedicated upper to the range to mesh a little with your results. It did not shoot groups today, it shot 6" patterns. Going to tear down the upper and reassemble. Of course, it could be the cheap scope I attached last night (Barska) but it is tight, so I am thinking the barrel doesn't like the plastic ATI upper. Going to put it in a PSA upper and see.
 
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