I attended my first Appleseed even last May. I earned my Rifleman badge in June using a Ruger 10/22 SS Walmart rifle and would like to learn more about other platforms. My Ruger performed well at the Appleseed and I was impressed with its precision (ability to put rounds in the same hole consistently). I tried using the Forum search feature and came up with little info about it.
I am wondering if anyone here has experimented with the CMMG conversion kits for the AR-15 platform. Did heavier subsonic ammo fire with more precision than a faster round like a HV or Hypervelocity round? I am asking because the rifling speed of an AR-15 (1 in 8" or 1 in 9") may over spin the round but I am not sure if that would even be noticeable. I am thinking about trying this with a 60 grain subsonic ammo.
I have also seen the CMMG dedicated upper that uses the same magazine as the conversion kit and comes with a 1 in 16" rifling rate. This faster rifling might be desirable for shooting CCI Stingers and may add to the precision but I would like to confirm this with actual range experiences.
Which of the following between a .22LR from Aquilla Subsonic 60 grain, CCI Minimag, CCI Velocitor, or CCI Stinger fired the best? I found a CCI product that is advertised to be good for AR platforms, has anyone had experience with that?
I plan to attend another Rifleman in October and I want to start buying stuff to get prepared for it. I did finally get my old Colt .22 M4 OPS (Umarex) flaws corrected and it seems to shoot about anything well. The CCI Stingers group well in Colt .22 M4 (Umarex) because it has about a 1 in 13.5" rifling. I don't own a .22LR upper and can't test it.
My friends and I have built 4 dedicated .22lr AR-15s, each a little different. 3 used Clint Beyer barrels and are extremely accurate. With Clint Beyer barrels you must use a CMMG conversion bolt. You don't use the .223 adapter part, but use a collar with a feed ramp. One thing we did on the last 2 rifles was use a S&W mag adapter made by Boonie Packer called Better Mag adapter. here is a link:
https://www.redi-mag.com/index.php?l=product_detail&p=52
The S&W mags are available and reasonably priced, and the rifles have been almost failure free.
We all use CCI standard 40 gr round nose. The barrels have a match chamber so using stingers is out.
Conversion kits will only get you about 6 MOA groups. A 22LR is .221 diameter an AR bore is .224 so the LR bullet bounce down the barrel like a ball in a Brown Bess and is about as accurate. If you want a tack driver you need the complete upper not just the conversion kit.
Just my observations on the line,
Chuck
Why convert at all? If you've qualified with a 22 already, why not run your AR with centerfire and tackle that mountain? Put what you'd spend on a dedicated 22 upper towards ammo.
Quote from: Guardian on August 02, 2016, 11:07:03 AM
Why convert at all? If you've qualified with a 22 already, why not run your AR with centerfire and tackle that mountain? Put what you'd spend on a dedicated 22 upper towards ammo.
That is one very good & valid point. You can actually now find 5.56x45 on the shelf now and it is not prohibitively expensive.
If you look online you can find it under .35/round including shipping.
The SIRT laser training bolt is on my short list of training aids along with the LASR software.
http://lasrapp.com/store/lasr-laser-activated-shot-reporter
Glock1911 is the voice of the software. TPU is the discount code from his website.
My husband had the CMMG kit in his mostly Rock River AR. It was not worth it. It suffered a great many malfunctions, so much that the rifle is now permanently named "Grumpy," and eventually caused enough additional stress on the two-stage trigger that it snapped in half. I don't recommend it at all.
I do recommend RR because they replaced the broken trigger immediately. Their customer service was excellent, and since abandoning the .22 conversion kit, the rifle doesn't live up to its name anymore. :)
I've seen two different .22 conversion kits at AS events, not sure of the brands, but neither of them were worth anything more than paperweights... :-\ Don't waste your money, too many malfunctions and inaccurate groups.
This video has some info which then made me buy the conversion kit! Have yet to try it out yet tho.......
https://www.youtube.com/watch?v=rSNT-5OnT0w
Guys,
Here is my story. After buying my first AR I then bought a .22lr conversion kit. Worked great, but accuracy was not what I wanted (8 1/2 x 11 groups at 25 yards). I then bought a dedicated .22lr upper to use with the AR lower. Less than satisfactory results.
This is what I found: Conversion kit; .22lr is a smaller diameter that ,223/5.56. I suspect that the bullet sort of "bounced" through the barrel. Second, barrel twist rate for my AR is 1 in 7. Adequate twist rate for a .22lr bullet is in the vicinity of 1 in 16.
I then decided to build a .22lr frankenupper. Used the receiver from the old upper and the some of the firing control parts from the conversion kit, bought a .22lr barrel and a free float handguard. I now have an upper that works flawlessly and is as accurate as my ruger 10-22.
It can be done.
aj
Building a dedicated upper is the best solution. Make sure to get the Better mag adapter also.
http://www.opticsplanet.com/cmmg-inc-22lr-mk4-barrel-kits-w-bolt-group.html
https://redi-mag.com/index.php?l=product_detail&p=52
This is an old thread but I have some relevant information. I have tried the CMMG conversion, CMMG dedicated upper, and compared them to the performance of my two Ruger 10-22s with 22" barrels.
The CMMG Conversion is cool and allows you to use the 5.56x45 AR rifle setup but that is about the only plus for it. The conversion lacks the precision to be a serious contender for 210. I am currently in the process of building a new upper with my conversion unit. I ordered a 20" Government Profile .22 LR barrel from CMMG. Unfortunately it is back ordered and will not get to me before my next Appleseed. The conversion kits can be swapped over to a dedicated upper by buying a barrel and Barrel Collar (https://www.cmmginc.com/shop/barrel-collar-assembly-22arc-ss/).
The CMMG dedicated upper with a 16" barrel has been a much better setup. It however can't compete with the precision of my two Ruger 10-22 with 22" barrels. I want to test a hypothesis of mine that the longer 20"+ .22 LR barrels will deliver more reliable results. I also plan to buy some subsonic .22 LR the next time I am in Bass Pro or Cabelas and test them in this CMMG dedicated upper. I will also add that I have the Redi-Mag adapter that allows me to use the S&W M&P 15-22 magazines. This has been a great upgrade because the rifle feels and acts like a real AR on the last round bolt hold open. The magazines drop freely with a push of the mag release button instead of having to be pulled out when using the Blackdog magazines. The bolt release button works every time when firing the last round of a magazine. It however is hit or miss if you pull the charging handle back while an empty mag is in the mag well.
I am thinking that the longer .22 LR barrels discharge the bullets at a subsonic velocity. If the rounds exits the muzzle at a subsonic velocity, it will not transition through the trans-sonic region of instability and thus deliver more predictable results.
The CMMG dedicated .22 LR on an AR-15 lower is a much more fun gun to shoot than the boring Ruger 10-22. I scored rifleman with the Ruger 10-22. Sometimes the better tool is not the fun one to use. If the subsonic ammo brings the performance of my CMMG up to the performance of the Ruger 10-22 or the longer 20" CMMG barrel is as precise as the Ruger, I would go with it over the Ruger. The Ruger is the best choice for shooting a 210+ AQT at this time.
I know at least two people who shot rifleman scores with CMMG conversions. Not the easiest thing by any stretch and I would in general not recommend it. But ut can be done. Both shooters were using 1:9 or 1:12 barrels and using minimags. I have not had good luck with standard velocity ammunition in conversions and non tuned semi ARs.
I have a Compass Lake that will run it. But it was built to do so.
I built a dedicated .22 upper with a Tacom ULW barrel and with the Targetmaster bolt/carrier. Using the newer generation black dog mags, it has performed very well, with no FTF or FTE problems. Shot a 581 in a CMP rimfire sporter match with it first time out while chasing holes in the slow prone, as I didn't get it zeroed right in the prep period. Every bit as accurate as my purpose built 10/22 CMP rimfire sporter rifle (with usual bolt, trigger & barrel enhancements).
I used a CMMG conversion kit in my AR at every shoot, and qualified. The secret is to try as many brands of ammo you can get your hands on, and see what your rifle/conversion kit combination likes to eat. My take-out-of-state rifle has a 16" barrel with a 1:7 twist, the kit and Black Dog Machine magazines. It seems to like heavier bullets, lower velocities and, probably most importantly, bullets that have some sort of waxy coating on them. I suspect the coating keeps the bullet from "bouncing down the barrel like a ball in a Brown Bess". ;)
Before heading out to my last Appleseed (RBC Ramseur 10-16!), I test fired the .22 I had on hand. These were at 25 yards.
First was Winchester M22, 40 gr, 1225 fps:
(http://i.imgur.com/KLfjdlG.jpg)
Ugh. Very inconsistent, 10+ MOA. Typical of bulk pack ammo.
Next, Federal AutoMatch, 40 gr, 1200 fps:
(http://i.imgur.com/5LnL8iu.jpg)
About the same performance as the Winchester. Nope. Not qualifying with that stuff.
Next is Aguila SSS "Sniper Subsonic" ammo. These things are wacky. They're more bullet than case, and send a monster 60 gr bullet downrange at 950 fps. The smoke stinks and make my eyes burn. I wouldn't want to be shooting them all day at the range.
(http://i.imgur.com/OFDnHE8.jpg)
The performance, however, is much better than bulk pack ammo:
(http://i.imgur.com/Hbbl9w0.jpg)
Eley Club (40 gr, 1085 fps) is what I used the first time I qualified, so I already knew its performance was acceptable. I also tested Eley Match, at more than twice the price of Eley Club, before that shoot, and it didn't group as well as Eley Club.
(http://i.imgur.com/FcKh7pz.jpg)
Finally, I tested Gemtech Silencer Subsonic (42 gr, 1020 fps). I had never used this ammo before. It sounds awesome in Gemtech propaganda, since I shoot with a suppressor at home:
After years of recommending various brands and types of ammunition, we decided to do things right and create our own optimized round for suppressor usage. Putting together a heavier bullet, a cleaner powder, a premium lube on the lead round nose projectile gave us consistent velocities and harder hitting performance at subsonic, suppressor-friendly speed. The 42 grain lead round nose bullet is heavier than traditionally available rounds, but isn't so heavy as to cause instability. While "harder hitting" and ."22lr" aren't usually associated together, steel silhouette shooters will appreciate the difference between a knockdown and a wobbling target that stays up! A designed velocity of 1020 feet per second ensures the heavier projectile remains subsonic speed in most all firearms without resorting to anemic velocities.
OK, let's send it:
(http://i.imgur.com/Mumbg1C.jpg)
Sweet. Needless to say, a brought a trunkful of Gemtech to the boot camp.
The conversion kit has been quite reliable for me. I've had a few failures to feed or eject, mostly with bulk ammo. Didn't have any issues with the Gemtech. Remember to keep the rails lubed, as recommended by the manufacturer.
Granted, I get better groups, even with bulk ammo, with my 10/22. But I like the advantage of training on one platform. When it's time to go up to the long range, I just swap bolts, re-zero and I'm ready to go.
This target is a CMP 50ft target from one of my last matches. This is CCI Standard Velocity, Clint Beyer barrel, CMMG bolt with various other AR parts. (as mentioned in my post above) It is nearly failure-free. 6X scope (max allowed for CMP), 5 shots, prone w/sling, slow-fire.
The guys here in NE Ohio have built about 5 rifles like this. I have a complete parts list in Excel if anybody would like it.
The price may not be worth it to many.....about $1000-1200 total. I built mine several years ago for $900.