I asked a similar question in the M&P15 forum but I think maybe I should have asked it here instead...

Why the 15-22 instead of an ar15 with a .22 conversion kit?

A couple of reasons to purchase a 15-22 come to mind...

1) Cost. You can get a complete 15-22 for about $400. Getting a 22 conversion kit is LESS than that, UNLESS you get a dedicated 22lr upper receiver [~$500+], which brings me to point #2

2) Unless you swap out the barrel as well, you will be running 22lr in a 1:7 - 1:9 twist barrel (most 22lr is 1:16, I believe)

2a) Most .223 / 5.56 ammo is copper jacketed with no lead exposure. Most 22lr is not, and if it is, it's generally plated at best. This presents different fouling issues than a .223/5.56 typically does

2b) By not swapping the uppers, your sights will present a completely different Point of Impact vs Point of Aim.

3) The 15-22 is a fun gun in its own right.

4) In some states, rimfire firearms are allowed where a center-fire 'AR' is not. Stupid, I know, but this is the madness... Related to this, I don't know if the 22 conversion kits have 'compliant state models', ie, restricted magazine, etc.

5) You'll be helping piss off a certain segment of the population by getting BOTH...

Some of the .22 conversions are very picky on what kind of ammo they will eat. I have a CMMG and it will only work with Federal bulk 525 packs. I use anything else and it's a jamomatic. It's the reason I ditched it and went with the 15/22. Also, some of them you can't lock the bolt to the rear. There is an additional conversion piece for the CMMG conversion that will lock the bolt, but for me the mags would not lock back once empty. I could only manually lock the bolt to the rear. No such issue with the 15/22.

As mentioned above your sights would have to be adjusted for the .22. And I've seen 15/22's as low as $300. You could go a dedicated .22 upper. I haven't read much about those and I would be interested to know if they have ammo issues.

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To add to the above, the MP 15-22 magazines are comically easy to load, even without a loading tool.

The CMMG and similar magazines often require a tool and are still difficult to load.

I long term tested several CMMG dedicated .22lr ARs and they were horrible. Reliability was sketchy. Accuracy was extremely poor as at 50 yards, I was happy to stay on a 8x11" piece of paper. I'm guessing that this was because they merely converted a standard CMMG AR to .22lr with a chamber insert permanently installed and addition of the bolt kit. Looking down the barrel, you could see a ring where the .223 chamber ended. It's too bad, too, I wanted to like them because they were exactly the same weight and balance as a regular AR.

At the same time, I (we) tested a similar number of MP15-22s, with the same ammo variety, same courses of fire, etc and experienced none of the same problems.

From personal experience, DO NOT get a conversion kit. Accuracy & reliability is HORRIBLE. Sorry I don't often yell but I initially went that route & was completely disappointed. From that horrible experience I purchased my first 15-22... and never looked back.

Only other option I would consider would be a dedicated 22 upper for the AR, but for me that did not make sense. With a 15-22, you get the complete rifle and for less than just the ar upper.

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That's funny, because my experience with the CMMG dedicated upper was the complete opposite. I purchased a CMMG Quebec-A (complete rifle with mil-spec lower) and my upper has a .22lr barrel with a 1:16" twist.

We have both the CMMG and the M&P 15-22. Accuracy wise, I give the nod to the CMMG. However, my son's M&P 15-22 has a higher MTBF than my CMMG. I have to do a little mini cleaning and re lubricate after about 300 rounds on the CMMG, where the Smith just keeps going.

Out of the box, the M&P 15-22 mimicked a true AR better than the CMMG with the bolt staying locked open, even when the magazine was removed. CMMG bolt would lock open, but once you remove the magazine, the bolt closes, requiring you to pull the charging handle once again to make it ready to fire.

I did add a kit to my CMMG that provided true bolt hold open, and at the same time converted it to accepting the M&P 15-22 magazines. I never found the CMMG mags difficult to load, but the S&W magazines were more readily available, and I wanted the bolt hold open feature.

Sorry to ramble on, but that is the comparison I have made while having both side by side at the range.

Awesome responses!
Thank you

I recently picked up a M&P 15 and a cmmg bravo stainless 22lr conversion kit. I would Highly recommend it. Point of aim is almost dead on Vs 223, it eats everything and it will put all 25 rounds on a 6" circle at 50yds with open sights. Yes it could be more accurate but as a plinker this thing rocks! If I want to put all my 22's through the same hole I'd never choose an AR with open sights anyways . My cz455 will out shoot an AR in 22lr All Day. I see no reason to waste $ on a dedicated upper or a separate rifle myself although I'm not a forum armchair "expert" like some around here that brag about all the bolt on's on their AR's and have little actual experience.

The cmmg conversion and a brass catcher are the only "furniture" I got for my AR. It shoots darn good and runs like a sewing machine! Good luck whatever you do and be safe with your new toy!

I would like to make one point here, though I state up-front that I'm a newb.

In any case, I did some reading, where I could, about the CMMG .22 LR conversion kits. What I believe to be true, from what I read, is that initially they were not stainless, and some had issues. The ones now are stainless/new models, and most of the "bad" reviews I saw were from the OLD style (if I am not mistaken). The reviews, from what I can tell, have been more positive on the new stainless ones.

I just purchased a new M&P Sport, and the CMMG "Bravo" stainless conversion kit. I haven't fired a round through the rifle yet (5.56, .223, OR .22LR), but will, soon. I can report back my results, once I have, but I wanted to share that thought (about the "old" conversion kits vs. the new ones), at least as I understand things (please someone feel free to correct me if I'm wrong).

I do realize that given the barrel twist, the Sport's barrel is not optimized for such a small round as a .22LR, and so I expect it will not be as accurate as a dedicated .22LR rifle. However, accuracy is not my overriding concern when shooting .22LR; becoming more proficient with my weapon, is. My plan is to shoot lots of .22 each trip to the range, and then finish up with a mag or two of .223/5.56. There may be flaws in my plan, or in my equipment (conversion kit), but I can adjust as I learn.

Steve

This target was at 50yds. Cmmg 22lr conversion on left with Winchester bulk ammo, my 223 reloads on the right. NO sight adjustment and holding in same place on both targets . Oh and admittedly I could be a WAY better shot... Don't get to practice enough. Still getting used to shooting the AR platform with open sights. Love this gun it's a ton of fun.

Please don't take my 15-22 away. I also have a S&W AR15, and I would not use a conversion over the 15-22 for any reason. One, if you have kids or grandchildren, the 15-22 makes a great training gun, also consider the ammo cost in the equation. The 15-22 without a doubt is the best gun purchase I ever made, and I have a few really nice guns. So I really believe getting the 15-22 would increase your joy and esteem greatly. Enjoy.

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How accurate is the 15-22?

When I was in the Army, my qualification with the M16 was Hawkeye

Therefore if I go with a .22 AR, accuracy is important to me.

Let's see some 50 yard targets shot with a 15-22 and open sights I'm curious about this as well......

The 15-22 is not a tack driver, but neither will a 22lr conversion. General accuracy is 2-4 MOA with bulk ammo. Some rifles perform better than others. Also, the barrel nut is famously slightly loose in many cases, from the factory. Tightening the barrel nut (CLAMP THE BARREL!!) is easy with the right tools.

With mine, clay pigeons (4") and soda cans (3" x 6") at 100 yards with a red dot are easy pickings. As with everything, ammo tends to play a huge factor in accuracy, given that at 100 yards, the 22lr will go transonic; standard velocity / subsonic ammo will tend to be more accurate as a result.

HTH...

With my Ruger 77/22 mag, I hit quarters at 100 yards

OK, but how does your M&P 15-22 run in comparison? I mean, surely you wouldn't post on this forum, trashing the experience of the other posters, unless you had extensive personal experience shooting your own 15-22, right?
Because otherwise that would make you a forum armchair expert who likes to brag but has little actual experience...

Anyway, I will join the other members here with actual experience on an M&P 15-22 and say that in my opinion, it is an excellent .22LR AR-pattern rifle that mimics the operation of my AR-15 in all functional aspects.

How could you possibly know how much experience anyone around here has? Why would you possibly say such a thing?
There are all sorts of folks here. Most are helpful & nice. Some with lots of experience with rifles... some beginners. As we sometimes see, some are jerks.

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Because the 15-22s run reliably. I bought two 15-22s for NSSF Rimfire Challenge. They're like the energizer bunny, they just keep running.

I based my choice on shooting and ROing steel and bowling pin matches etc. and seeing what guns were running and which were having issues. The 15-22 was the clear choice. Two yrs of Rimfire Challenge Matches plus assorted steel and bowling pin matches has shown it was the right choice.

I've changed nothing to make it more reliable. I have added a Geissele trigger group, C-more, and a few mods so it fit me better. In fairness, the Giessele trigger group has a heavier than stock hammer spring.

It's a 3 moa gun as others have found. I have 2 of the 16" threaded barrel versions.

In addition (I don't know if it is true) but I heard that shooting CMMG could possibly clog your AR15 gas impingement sytem. My AR's are way more expensive to play with the dirt remaining from 22lr rounds, and it is dirty rounds to begin with. That is main reason I got dedicated 15-22 rifle and honestly I don't like pistol coversion kit's to 22lr as well so far.

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