kfd518
Active Member
I'm not sure if you got this sorted yet.
Dealt with my 6.5 not cycling to lock back by contacting the manufacturer once I realized the "matched" gas block was blocking 0.040" of the port. It was a rifle length+2".
In my experience a 5.2 oz minimum buffer is needed in all large frame AR builds. A good combo to work from that I have noted in my building has been anyone of the 5.2+ short large frame sized buffers with a sprinco orange spring.
I realized this on my first one when it was showing ejector swipes in mid January with factory match loads. It was un locking very early while pressure was still up in the chamber. The problem returned after I suppressed it. I did manage the last part of the equation with an adjustable gas block and I know the settings from one to the other and set the AGB accordingly now.
Another thing to verify as mentioned before is that you are not bottoming out in the LRE. Not enough weight, weak spring, to much gas will increase the bolt speed to a point that it cannot strip the round from the mag.
I diagnosed the short stroke of my 6.5 CM with my iPhone set to slow motion.
Dealt with my 6.5 not cycling to lock back by contacting the manufacturer once I realized the "matched" gas block was blocking 0.040" of the port. It was a rifle length+2".
In my experience a 5.2 oz minimum buffer is needed in all large frame AR builds. A good combo to work from that I have noted in my building has been anyone of the 5.2+ short large frame sized buffers with a sprinco orange spring.
I realized this on my first one when it was showing ejector swipes in mid January with factory match loads. It was un locking very early while pressure was still up in the chamber. The problem returned after I suppressed it. I did manage the last part of the equation with an adjustable gas block and I know the settings from one to the other and set the AGB accordingly now.
Another thing to verify as mentioned before is that you are not bottoming out in the LRE. Not enough weight, weak spring, to much gas will increase the bolt speed to a point that it cannot strip the round from the mag.
I diagnosed the short stroke of my 6.5 CM with my iPhone set to slow motion.