Well, I would agree that your setups are over-gassed to one degree or another (even though your BCM is a BCM, any 16" carbine gas barrel is gonna have way too much dwell time).
In my search for "reciprocal smoothness", there is no replacement for getting the gas port further away from the chamber while reducing barrel length in front of the gas port. With that said, you can take the concept too far.
I think this is why Wes at MSTN is currently experimenting with a 17" barrel running a rifle-length gas system (13"). His personal gun is set-up like this now and he's reporting 100% reliability so far.
There's no substitute for reducing gas port pressure. The LMT carrier has no effect on the pressure at the gas port, but it does affect the amount of time that the expansion chamber inside the carrier is pressurized. The increased length of the cam-pin track also allows the carrier to move slightly further to the rear before bolt unlocking begins (allowing chamber pressure to subside as well). These are all good things.
But, since the LMT Enhanced carrier design is substantially different from the original Stoner design, there is no guarantee that it will work in a given gun....one simply has to experiment. This is a complex equation; exact chamber dimensions (even within NATO tolerances), gas port placement and diameter, buffer weight, buffer spring compression strength and rate, etc. I won't even pretend to completely understand all the math....I revert to the guess-and-check method.![]()



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