I've heard of a few different brands of conversion bolt-carrier groups that can be dropped into a standard AR-15. What are your experiences with the different brands and would you buy them again?
I realize there are quite a few manufacturers nowadays making AR style .22's but I'm thinking that if the conversion kit works well enough I may be able to skip the "middle man" for my daughters so when they're comfortable firing the AR as an AR I could just take the conversion back out.
I have always shied away from the conversion since you are putting a .22 in a .223 barrel. Yeah it is 3 thousandths of an inch, but the bullet still has room to move in the barrel a bit which hurts accuracy and potentially the barrel. Last time at the range, I was shooting next to a guy who had the CMMG conversion and he dissapointed with its accuracy and what seemed to be overly fussy nature when it came to ammo. He said that if he could do it again, he would get either a dedicated upper or complete rifle like the M&P 15-22.
I myself have the CMMG dedicated upper and really enjoy it. It doesn't have the stainless bolt and all the fancy stuff, but it is still a blast to shoot and gives me decent groups with bulk ammo. I'm not out for one hole groups at 50 yds., but I am happy with the accuracy, usually sub-1.5" at 50 yds if I am doing my part. If I wanted a tack driver, I would have kept my 10/22 or got a savage bolt gun. This is just a trainer/fun plinker and it fits the bill relatively cheaply.
Changing out the conversion kit and changing out an upper are just as simple. The benefit of the dedicated upper is the that it is made specifically for the .22lr and not "converted" to work in .223 barrel. My opinion is get a dedicated upper from many of the companies making them now, CMMG, DPMS etc., or a dedicated rifle like the M&P 15-22, and save your centerfire barrel. The upper will pay for itself in the first 1000-1500 rds (depending what you shoot).
The conversion kits can be problematic for two reasons, 1 the ammo and 2 the barrel. Most AR15 barrels are between 1:9 and 1:7. A typical 22LR barrel can be 1:12 or even 1:16. If using lead nose ammo jams are frequent. Better to get something like the Winchester 22 LR FMJ which they named tactical, lol tactical 22 ammo.
Go for a dedicated upper if you ask me. I'd also shy away from the dedicated 22lr rifle because you have almost zero flexibility. SOmeone bought a 22, I think it was mossberg but I forget, and wanted me to put a 223 upper on it. I said no way no how. He thought he was getting a deal and thought he could swap the upper and havea regular AR. Well it doesn't usually work that way if you buy a dedicated 22lr rifle. Better get the regular AR lower and get a dedicated 22lr upper.
By the time your first kid out grows the 22lr, you'll be ready for another kid anyways
Having said that I decided to build my daughter a Ruger 10/22 I decided the AR platform will be too heavy for her to start with.
DPMS and CMMG are both good buys for the dedicated 22 lr uppers.
I have a dedicated .22 upper and a conversion. For your purposes, there's nothing wrong with a conversion, as long as you are willing to do a little work to ensure that your daughter's AR experience is enjoyable. You can even make it a father-daughter project: they'll learn a lot about their rifle. The CMMG kit is probably the most readily available. None of the conversions are going to be as accurate as a dedicated .22LR, but they can be greatly improved, both in accuracy and function.
As to accuracy, the typical 1-in-7 or 1-in-9 twist of an AR barrel significantly overstabilizes the .22LR bullet (which usually gets a 1-in-16 twist), which theoretically makes it less accurate, but that isn't terribly significant at the usual plinking / training ranges.
Most .22LR bullets are .223 - .224 diameter already, so there really isn't a bore diameter mismatch. It's a throat diameter mismatch (see below). So where does the inaccuracy come from? Mostly, two places.
1) The chamber insert itself has some freedom of movement within the rifle's chamber. To see how much slop you have, wrap a few turns of scotch tape around the mid-portion of the chamber insert until it snugs up. If that helps accuracy, you might want to groove the insert and install a couple of o-rings on it for a more permanent fix.
2) The biggest problem is one with which revolver shooters are familiar: the throat is too tight, and undersizes the bullet, which then rattles down the barrel. Functionally, the throat in this case is the adapter, not the rifle's throat. Many (most?) of them are bored to .221 inch or even less. Opening the insert's bore to .224 or so will significantly increase the accuracy. A little too big is better than a little too small: the .22LR bullets are quite soft, and will easily swage down to bore diameter as they go down the rifle's throat.
As to function, even the dedicated conversions can be fussy about ammo, and most want high velocity ammo. Friction is the biggest problem. The two biggest points are the feed ramp and the rails the bolt rides on. Shoot a hundred rounds and the wear marks will show you where you need to polish the rails. Some 600 grit wet and dry paper will handle those and the feed ramp. I prefer to do it by hand, rather than break out the Dremel.
The last thing you can do is replace springs. Much of the resistance to bolt travel comes from the hammer spring. Rimfire conversion specific spring kits are available to balance bolt cycling and hammer strike force, but that sort of thing makes more sense with a dedicated rimfire AR.
Thank you all for the very informative replies. Do the .22lr uppers simply drop into place onto a standard AR lower?
My older daughter has 8 yrs of experience with a .22lr and my lil daughter has 5 yrs experience. I feel like the older one is quite capable of firing a .223, she's just not too fond of the noise, although they both have ear muffs. I may see if she'd at least try it in .223 first. She's 14 and just about adult-sized lol
Yes, the dedicated uppers simply drop into place on a standard AR lower. Most use the Black Dog Machine magazines, get a couple of those and have a blast!
Unless you are dead set on an AR platform, for the price, a 10/22 is tough to beat. You can get one for under $250. Just another cog in the wheel...
Yes, pop two pins, remove old upper, insert new upper, reinsert pins. 30 second process.
Unless you want to to do like Big Pat said in regards to hammer springs, but I'd make that decision after a few hundred rounds to see if necessary.
If you want them to get familiar with the AR platform with a 223, you can really build a reduced recoil AR. Light loads, tuned gas system is an option. Most opt for stronger recoil spring and heavier recoil buffer with a mid or rifle length gas system and a heavy barrel. Don't forget the recoil pad, they make some good ones for the AR platform. If the "boom" is the problem look into a sound suppressor, I am not sure if they are allowed where you are at, because I do not know where you are at If you can't have a sound suppressor look for a good compensator which will help with muzzle rise.
I have always shied away from the conversion since you are putting a .22 in a .223 barrel. Yeah it is 3 thousandths of an inch, but the bullet still has room to move in the barrel a bit which hurts accuracy and potentially the barrel. Last time at the range, I was shooting next to a guy who had the CMMG conversion and he dissapointed with its accuracy and what seemed to be overly fussy nature when it came to ammo. He said that if he could do it again, he would get either a dedicated upper or complete rifle like the M&P 15-22.
I myself have the CMMG dedicated upper and really enjoy it. It doesn't have the stainless bolt and all the fancy stuff, but it is still a blast to shoot and gives me decent groups with bulk ammo. I'm not out for one hole groups at 50 yds., but I am happy with the accuracy, usually sub-1.5" at 50 yds if I am doing my part. If I wanted a tack driver, I would have kept my 10/22 or got a savage bolt gun. This is just a trainer/fun plinker and it fits the bill relatively cheaply.
Changing out the conversion kit and changing out an upper are just as simple. The benefit of the dedicated upper is the that it is made specifically for the .22lr and not "converted" to work in .223 barrel. My opinion is get a dedicated upper from many of the companies making them now, CMMG, DPMS etc., or a dedicated rifle like the M&P 15-22, and save your centerfire barrel. The upper will pay for itself in the first 1000-1500 rds (depending what you shoot).
TG
+1 on everything he posted. I have a S&W 15-22 and love it for plinking and it's a great training rifle because all the mechanical controls mimic the AR15.
The next best thing is to get a dedicated 22lr upper.....as stated.
I was thinking along the lines of if they had 1 rifle that could do just about everything, and they essentially grew up with it but never outgrew it, that that rifle's funtioning would be second-nature to them. We live in GA, and suppressors are legal here. Are there commercially made reduced power loads, or would I have to reload them that way?
I have owned 1/2 dozen of the Ciener Units over the years, with many thousands of rds fired thru them, and friends own as many more. sometimes they need some tweaking, but they run 100% thereafter. there is NOT .003" in diff of bullet diamters, there is only .001", and the lead bullet "upsets" in the bore to seal it just fine, as do cast lead bullets in pistols, which happen to be .001" undersize, which happens a lot, actually. 1 in 9" stabilizes them just fine, 2" groups or better at 50 yds, the POI is within 2" of 223 POINT OF IMPACT at 50 yds, too. no, the .22 does NOT 'lead up' the bore or the gas system, and even if it did, firing a couple of 223's every 200-300 rds of .22lr will scour out the bore and system just FINE. there is no point in having the dedicated upper, and having the .22 unit lets you walk afield, with a 20 second choice of 223 or .22lr. you can't carry the entire spare upper afield, so there is really no use for it. the dedicated upper, in many cases, still requires you to have the .22 unit, you know. very expensive proposition.
Basically, a .22 conversion will give you 2-3" at 50 yards.
A dedicated CMMG will give you 1" at 50 yards.
The trick with conversions is finding a good ammo/barrel combo.
I always recommend copper wash ammo. You will run a lot longer without leading up the feed ramp.
Straight lead will give you problems and Remington is probably the worst ammo you can use for dirt and reliability.
For cheap, I use Winchester 555 bulk from Walmart.
The other issue is a change in POI using the conversion with a 5.56 dial in.
It's close enough for training purposes but not for any kind of target practice.
And of all the conversions I have, I've never seen any reduction or damage to my 5.56 barrels.
I shoot 300-500 rounds of .22LR, then run a Boresnake through the barrel while warm and shoot 5 rounds of 5.56 to blow the gas system out.
Clean properly when I get home.
Dave N
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