The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

Its a good job someone knows what there on about or he would have ended up with a Bad Lever.

in case anyone else wants one:

http://emrr.org.uk/cmmg-bhoa-bolt-hold-open-actuator/

Only works properly with cmmg's own mags, as the mag follower is a little different, the edge closest the trigger has a little cut out so the follower can lift the bhoa into the path of the bolt when the mag is empty - whereas other mags like black dog - the bolt hits the follower at it's highest point.

The difference being, with a cmmg mag -drop the mag out and the bolt stays in place, with black dogs the bolt goes into battery as soon as you drop the mag out (unless you hold it open with bolt release / bad lever).

I had cmmg gen3 mags on my mk4 cmmg (20" barrel fwiw) but they were utterly unreliable so I switched to black dogs, tbh I don't miss the bhoa that much though I do think occasionaly about modding the mags to make them compatible.....

Sorted now and out of stock at East Midlands regional range.

CMMG BHOA can be made to work reasonably reliably but they are the weak link in the system no matter what magazine you use. The most reliable BHOA to be found for a .22 AR is the Boonie Packer S&W Better Mag Adapter, they work the Bolt Catch far more reliably than the CMMG BHOA as they have far more 'positive'contact with the bolt as can be seen in the photo below, the blueing wear shows the full contact area. No adjustment allen screws required either and the device is not sandwiched between upper and lower as it fits in the mag well, down side is you need to buy new magazines.