I've scanned through the 6 pages of posts, and also emailed CMMG a couple times in the last week or so, and got answers to several questions (not necessarily the answer I hoped for, but at least they did respond).
I'm wanting to build a dedicated 22LR rifle, and already have a complete lower ready to use. I think I've decided two things:
1. I'm going with the 16" M4 with the receiver height gas block
2. I'm spending the money on the SS upgrade
That looks to be the only decisions I can really make at this time. No other options/upgrades are available. Which leads me to the following questions:
1. I'd like to set this one up similar to my others, with a red dot and a set of Magpul MBUS sights. That's the reason I'm going with the receiver height gas block. I know Magpul says not to mount the front MBUS on a railed gas block due to heat, but all the threads I've searched seem to indicate that wouldn't be an issue with a 22LR. Agreed?
2. Since the gas block is really non-functional, can it be moved forward in order to install a mid-length handguard? (I'm fairly new to the AR world, and not exactly sure how a non-functional gas block would be attached. My first thought is I'm "stuck" with the carbine length, which isn't a no-go for me).
3. I see the upgrade says SS bolt & collar w/ FA. Would I still need the Adapter Assembly, Forward Assist, RH that's they sell, that "allows full function of your rifle's existing forward assist."? Not exactly clear what the upgrade does in regard to the FA.
4. I also see the BHOA offered. Then notes/posts about it only working with Evolution mags (which are apparently no longer available). I did grab several BDM mags with steel lips that I plan on using. Do I need to buy the Bolt Hold Open Kit? At a minimum, do I at least need to get a 22LR bolt catch spring or cut a couple coils off my current one?
5. Anything else I haven't thought of that would be obvious to a more experienced shooter?
Thanks in advance.