i was wondering if anyone has the cmmg ar-15 and if so what is the action of the bolt hold open since i see nothing happening on mine and just wondering if there is a issue with the cmmg’s or if its just my rifle specific
thanks
SEMPER-FI
If you are using the .22 hardware, there’s some info on your gear in this video - << http://www.youtube.com/watch?v=p9fF1Ar5JWs >>
Enjoy!
semper-fi, are you asking about a .22 LR rifle, or the bolt hold open function in general? what is it not doing that it’s supposed to be doing?
i was inquiring to the cmmg .22lr the boha does nothing on mine and per cmmg website the mags that have the boh follower are black on top,and the one sent to me is green also in the well of the rifle there is no boh actuator like i would assume there should be since it is advertised in the specs i mean why would they include the follower in the mag but no actuator that would be just plain stupid
thanks
SEMPER-FI
moved to the correct section.
Can’t speak to that particular rifle, but on most of the magazines, the follower just holds the bolt open after the last shot, and then drops the bolt when you drop the mag. There’s not a mechanical BHO on the kit/rifle on any conversion that I’ve seen…
I have the BHOA in my CMMG .22lr upper and run BDM mag’s. The BHOA is a separate $12 piece that is inserted between the upper and the mag well opening in the lower. It is actuated by the rifle’s bolt release. The BDM will hold the bolt open on the last round(like you said) but with the BHOA it allows me to hold open and release the bolt with the rifle’s bolt release. Don’t know if that was any help, because I am not quite clear on what you are looking for. 
The CMMG BHOA is a drop in part that locks the bolt back after the last shot is fired, like the 5.56. It rtequires BHOA mags to operate automatically. The bolt is locked back even when the mag is removed.
I use mine with standard mags also, locking the bolt back manually.
BDM mags, CMMG standard mags, will not automatically lock the bolt.
The BHOA is $19.95 from CMMG.
The BHOA mags are $25 for Gen l and $30 for Gen ll.
In testing, the biggest issue I found with the BHOA not operating properly was the tension of the bolt catch spring.
I checked 5 different lowers from various manufacturers and the depth of the BC spring hole varied. This gives varied spring tension.
The BHOA mag spring has to over come the BC spring tension.
I clipped 1 or 3 coils off the bolt catch springs and have good reliablity of the BHOA.
It’s hard to make a universal anything with so many tolerance differences from one manufacturer to another.
Dave