The Cous De Grace short action is designed to run AW mags period. They do not work well with aics(both of mine are early production, they will not even accept an aics mag into the mag well). You need a dbm/chassis that has an adjustable latch as well to keep the mag seated up against the mag cut in the action.
This is paramount with any rifle running aw mags. I have a 65cm and 6gt on the CDG action, prob 1800+ rounds between the two, and once I tuned the aw gt mag properly, I've never had a feeding problem with either. The 6gt is a loaner rig and a lot of novices have ran it, with no problems.
If a guys building around an action designed for AW mags, he needs to know what he's getting into and have things set up properly, if not, you're stacking the deck against yourself. Aics mags can be over inserted into an AW mag cut and cause a bunch of issues there as well.