I just installed a PTG DBM in my McMillan HTG stock, and noticed that the AICS magazine does not fit tight in the mag well. I was afraid that it would fail to feed, and sure enough, it does not feed. I can push the bottom of the magazine up, and it feeds fine. The magazine is a factory AI .223 mag. Is this something unique? Does the DBM not work with the .223 mags? I would think that the mags all seat at the same depth, but this mag almost feels sloppy in the mag well.