I have a 223 Accurate Mag mag I would part with.
The MDT mags can be found here:
http://mdttac.ca/magazines.html
Haven't tried the yet, but the COAL is longer than the steel mags, like the AI.
Just ordered some mdttac mags...we will see how they work.
Cheers!!
When you get your rifle all put together you will have to post some pics!