Does your magazine seat fully when using that barrel? I don't see how the barrel really could affect the magazine seat. Perhaps lock the slide back, insert a full magazine, and see if any part of the barrel prevents it from seating correctly. Other than that, the obvious question would be, "when using that barrel, does it affect your grip to where you may be pressing the magazine release button inadvertently?"
__________________
M&P40c/15-22/SD9VE/Mossy500
|