How exactly does LRBHO work?

[egd5]

I know what it is, but what makes it function. Is it a catch or something on the bolt, or where? And if a gun locks open with rounds still in the mag is that a part of ti going bad?

Oh, I'm talking JP, but would it apply to any gun?

[DesertTortoise]

The magazine follower engages a tab on the lower receiver that looks the bolt to the rear. I believe the AR 9 style does this by the follower pushing up on the ejector which then engages the bolt catch. 

 

 

[Hawk21]

Best option if you have to have it is New Frontier!

 

copied from their site:

 

QUESTION:   Do you offer a reliable last round / empty magazine bolt hold open (LRBHO) System for this lower?

ANSWER:  YES — After watching several companies try and fail to incorporate a RELIABLE last round bolt hold open (LRBHO) system into their lower receivers we decided to take a different approach and will be incorporating our LRBHO technology (PATENT PENDING) in our matching upper receivers.  After rigorous testing and hundreds of hours of research and development we feel that this is the best option for LRBHO on a Glock magazine AR style firearm.  Our upper will be compatible with other manufacturers lower receiver that either don’t have a LRBHO or you can scrap the non-working LRBHO out of your existing AR-9 Glock Mag lower and solve the issue of not having a 100% functioning LRBHO.  For more information on our matching AR-9 Upper, please CLICK HERE.

[ampleworks]

QC10's system was flawless for me until I installed a JP short stroke. Of course, to JP's credit they say bolt hold open isn't going to work so I just pulled it out completely. I had to change my unload/show clear process but no different otherwise. If anything, letting the bolt slam away from hold-open onto my flag has decreased the wear on my flag.