i have an SWD m11 that has a magwell so tight that i have to use a lot of force to insert and remove a mag. got to looking and notice a very slight concavity in the well like this (exagerated but you get the point).
i can spread it out a hair but unsure the best way to do it. drive a mandrel thru the well or use some kind of spreader???
i am afraid to start taking too much metal off the mags. the poly mags i have would not hold up very long if i thinned them down.