CMMG Dedicated .22LR Stainless Steel BCG - $140.47 after Code: "VETERAN25"

My long post aside. I don't know why anyone would spend an extra $45 on the cmmg BCG when the RTB branded one is made by cmmg and $115. You just don't have to pay for the name. And it's cheaper with the TOBER10 code for another $11.50 off.

I paid $290 for one of their 9" complete uppers with the buildup 20 code. Added the bore Buddy reliability kit, 8 kriss mags (during their 30% off sales). Use it with an SBA brace and holosun 512, and it's been reliable and pretty accurate. Can hit 8" steel at 100 yards and a little tighter if I'm sitting at the bunch. Ended up building a 16" with a blem barrel too and just swap the bolt. But I use the shorty for carbine classes doing all sorts of moving drills.

I like keeping the 5.56 separate. And am building a 9mm pcc and was thinking of SBR'ing a lower in January, picking up bear creek's buffer less 9mm upper and use the lower for the 22 and 9mm. And then add a folding stock for the backpack.

What good is this if you can’t get a barrel?

When you can find the conversion kit w/ mag(s) for <$140, and you can buy the conversion collar for ~$45, this just seems like it is priced too high considering you then have to get the conversion barrel before you can even use this: if you get the standard conversion kit, you can at least use it until you save up the $ for the conversion barrel & replacement collar, and meanwhile, you don't have to shell out extra for mags that don't come with the dedicated bolt kit!

This is a vote leaning towards the dedicated bolt and either the cmmg barrel w/collar or an even higher-end dedicated barrel like from Beyer. Here are some reasons:
1) The conversion kit is a smoothbore chamber adapter and bolt that feeds the 22lr round into a .223 barrel that is slightly oversized for the bullet and completely the wrong twist rate ie. 1:[7,8,9] vs 1:16 (of course, it would still be fun, just don't expect match accuracy)
2) Going the dedicated route will definitely be much more expensive that then $150-$180 conversion, but you'll end up with a rifle that is better than the S&W M&P 15-22 (as an example alternative). The S&W reportedly have the best mags and if you want to use them, there is an inexpensive adapter you can install in any AR lower that "allows for full bolt actuation as well, lock back, lock back on last round, release, etc. Makes it just like the real thing" (credit: cj3waker on rimfirecentral.com)
3) Using dedicated also means you won't needlessly be sending any rimfire gas or fouling into your gas setup as the dedicated is strictly blowback operated and doesn't use a gas block at all. Not sure how big of deal that is but I figured I would mention it (some say it is a non-issue, so YMMV)
4) At least a few owners have reported sub-MOA performance from the dedicated setup with good ammo, so if that is important to you, the conversion may have a hard time getting to that level even with high quality ammo
5) My personal take is to get both if you can afford it. A conversion to carry about in your range bag for fun/plinking and a separate dedicated AR-22 for when you want to wring out absolute performance from the platform in 22lr. With 22lr prices returning to "normal", these parts pay for themselves really

Happy shooting,
-JNFoo

I would recommend passing on this and getting the conversion kit with 3 mags then picking up a barrel/collar combo. The conversion kit is often 180 or so with (3) 25 round mags.

You come out better in the end than getting this, then buying a barrel, then sourcing mags

These are expensive but they do increase the accuracy of the 22 long rifle round used with a dedicated cmmg 22 barrel versus the conversion kit that fits in any AR15.