Great 22lr conversion for your ar15 clone. - CMMG, Inc 22LR AR Conversion Kit, Bravo

The big question is, do you want a conversion kit, a dedicated 22lr upper or a complete gun? This is the best AR15 22lr conversion out there and it's popularity & price speak for itself. But with the limitations of a conversion kit come a couple issues. 1st and foremost, due to the kit needing to function with a maximum number of mil spec AR clones, the action is way too stiff and the mags are pretty dang big and heavy for 10 rounders. More on that later...
This kit functioned (almost) flawlessly with premium ultra velocity 22lr, but would not take the cheap stuff. Likely after a few thousand rounds (I'm currently at around 800,) the spring would soften up and cycle generic high-velocity ammo, but outta the box it wants only good quality 1200+ ft/second stuff like Aguila 22lr Super Extra 1280fps.
If I'm using good, high speed ammo, it shoots great and outside of a couple stovepipe, it's been wonderful. If you try Walmart's cheapest federal white box? You're probably gonna have a single shot cause the bolt won't fully cycle.
The only mags that are widely available are the CMMG 10 round pinned mags. Most websites are out of the 25's. Frankly, a 10 round mag should not be as big and heavy as a standard capacity AR mag. This is super easy to remedy with needle nose pliers, an Allen wrench and a utility knife. The only thing keeping these mags from holding a standard capacity is an easy to remove stainless steel pin. This will not help you, of course, if you live in a ban state, as modifying mags to allow them to function as intended may be a felony in your state. YMMV.
I would highly recommend this to AR15 enthusiasts on a budget. It's a ton of fun and a great training tool since you keep your actual AR15 trigger and optics. It will hit low compared to 556 due to 22lr velocity, but that's easily remedied if you don't mind re-zeroing your optics.
At 200 to 250 bucks it's half what you'll pay for an a nice 22lr ar style rifle (I'm looking at $500 plus mags for a S&W 15/22, which is a really nice gun but not actually an ar15 clone,) or a third of what you'll pay for an actual ar15 clone in 22lr. So if you wanna save money, you want this. If money isn't an issue? Get a complete 22lr upper from CMMG instead, supposedly they're really nice although I've not seen em in stock.
On that note: you will hear people say that 22lr outta an AR15 barrel is inherently inaccurate due to the larger barrel size (556 NATO barrels are around a thousandth larger than 22lr barrels.) This was not the case on either of the ARs I shot this in. Accuracy was very good, and more dependent on ammo quality than barrel.
Overall, I would definitely recommend this to AR15 owners who wanna save money on ammo, get new shooters into the sport without worrying about recoil or just wanna have a fun time at the range.