Springfield XDm 45

[Mookie]

I have an XDM40 and have been told repeatedly, the mags are not interchangeable with the XD

This is true. The M had the mag well opened up to be able to fit the larger capacity magazine. Nothing else could have been done with the exception of making a taller mag.

[DeerHarvester]

I have an XDM40 and have been told repeatedly, the mags are not interchangeable with the XD

This only applys to the new XDm45 and standard XD45. The mags are exactly the same on both 45s. Your are right about the XDm40 they made larger mags in the M factor.