Hopefully the information below will help alleviate the anxiety being propagated that the AT-X has fundamental flaws. For those who are just here to stir the pot, there is nothing I can do or say to fix you.
First:
The discussion about the magazine follower holding the bolt open on empty is ill informed. For a very long time the 6677 and 0726 magazines may or may not hold the bolt open on empty in the AX, AT, and AT-X rifles. This has everything to do with the magazine tolerances, spring pressure and fit of the magazine follower against the feed lips. Magazines are a stamped, folded and welded component that undergo surface treatment processes and will always have more tolerance variation than machined parts. We had a product meeting in the recent past and the magazine's ability to hold the bolt open got a lot of discussion. What was interesting is that there was no agreement or organizational "memory" of such a requirement. Some members of the meeting wanted the mag to always hold the bolt open on empty as a "military" feature, and others, including myself, want the bolt to ride the follower down on empty. The overwhelming majority of customers in the U.S. want the bolt to ride the follower down on empty. If your magazine is holding the bolt open on empty it is a simple matter of putting a 45 degree chamfer at the rear of the follower with a Dremel or a file.
Feeding Problems:
Shimming your mag catch is at best a bandage applied to something that isn't a root cause of feeding issues. If your AT-X isn't feeding reliably we need to send you a new magazine or adjust the magazine(s) that you have. The 6677 and 0726 magazines were/are designed to feed .308 WIN rounds and for many years they have worked perfectly well with the 6.5 Creedmoor rounds. A recent investigation of processes in our magazine press cell highlighted same areas for improvement in feeding reliability with both classes of ammunition. We have had some recent production lots of magazines where the width at the top of the magazine at the retention ribs is at or slightly under the minimum tolerance. This is never a problem with the 308 as that round is smaller in diameter at the body to shoulder junction than the 6.5 CM, (.454" vs .462"). When the width of the body becomes narrow toward the top it tends to squeeze the round stack at the front creating space in the round stack vertically. This can allow the rear of the stack to squat reducing engagement with the bolt. If the bolt is contacting the chamfer of the case head it will simply ride over it. This is easily corrected by slightly stretching the top of the mag but it must be done with care. The best solution is to contact AINA and we will send out a new mag or adjust your current mags. The photos below illustrate an extreme example of the stacking issue.
View attachment 7843643
The magazine body has a compound taper by design. At the bottom of the mag where the base plate is welded, the width and taper is correct.
View attachment 7843644
In the image below, the magazine is trending narrower at the top thus forcing the front of the rounds deeper in the stack. At the rear of the mag where the width is within tolerance the rounds slump due to the follower being held too low by the constriction at the front. This condition is easily corrected and if you have magazines with these characteristics we would like to get them back for adjustment. We can generally return ship them the same day.
View attachment 7843650
Several measures are being implemented in the magazine operation to ensure mags are produced that stack both 308 WIN and 6.5 CM rounds optimally.
Do I need a shim?:
NO!
IF you are a U.S. customer, please don't contact us asking for a "shim kit". There are no shim kits and there isn't a need for them. Shimming the catch to hold the back of the magazine up higher will do nothing to change the width of the magazine at the retention rib, and you may induce new problems by changing the orientation of the magazine.
The number at AINA is 540-368-3108
M-T 8:30 am to 5:00 pm and 8:30 am to 12:00 pm Friday.
-Scott
. Nah I’ve stopped asking mate ….I’m sure the boys are sick of it, it’s out of their hands. Last Danny said was end of April for the black 
. I’m not fussed anymore 
Hope your rifle comes in soon!!
