Must be out of spec since it is brand new...
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Possibly. With the way companies are cranking out parts and rifles, I think QC has slacked a bit.
I didn’t consider your carrier group being fairly new. By out-of-spec I had a used carrier key in mind. If the gas tube to carrier key fit is not exactly right, the gas tube can wear on the carrier key. Over time this elongates the carrier key gas passage causing excessive leakage.
It could be an improperly drilled carrier key gas passage or partially blocked carrier key gas passage. I’m sure you probably already checked the carrier key for security. It could also be a poor carrier key to carrier fit, causing excessive gas leakage where the two mate up.
You could still check the above. Now that you know for sure the carrier group is at fault, it should be a easy fix.
Jcrowl (seller) from arf dot com is ordering a BCM Auto BCG for me and will have it shipped directly to me In return I will send him the faulty BCG so he can send it back to LMT for repair/replacement.
Jcrowl is a standup guy, I never asked for anything but info on parts used but he apologized & suggested to get this Carbine fixed on his expense. Even tho this Deal wasn't made on this site I think it is worth mentioning because great guys like that are hard to come buy.
Thanks for all the Help guys!
Which reminds me.
Quib have you ever seen a spec/tolerance on what the diameter of the raised portion/nipple end of the gas tube should be?
Ive seen some rather large differences in the replacement gas tubes recently.Some have a distinct raised ring and others not so much.In that regard some fit extremely tight in a gas key and others are flat loose.
I may have misunderstood this.
I originally thought something might be lodged in his receiver extension preventing the bolt carrier from traveling fully to the rear. When he pulled on the charging handle he got the bolt back far enough to strip a fresh round. But, when the weapon fired, it could not travel back on its own far enough to strip a fresh round.
It can be a task sometimes, trying to troubleshoot a weapon malfunction over the internet, without the weapon literally in front of you. All a person can do is try to interpret the individuals description of the malfunction, and start tossing out possibilities for a corrective action based off past experience.