You may have a big collection of AR-15 magazines.  Or maybe you don’t want to spend upwards of $40 apiece to build a collection of Steyr magazines that will only work with your AUG. In either case the Steyr NATO stock is a welcome option.  I bought a conversion kit, which consists of a modified stock and trigger pack (a.k.a. “hammer group”), from CDNN for $300.

Top: Original AUG stock, trigger pack, and magazine. Bottom: NATO conversion kit, shown with an L5 magazine.

Shown here (top) is the original AUG/A3 stock and trigger pack and (bottom) the NATO Conversion stock and trigger pack, with Lancer’s transparent L5 AR-15 magazine. Like all AUG stocks the NATO stock is molded with a bump on the top receiver end. To accommodate the A3 receiver’s extended top rail this stock bump has to be cut down — an operation I was able to complete in just a few minutes with the careful use of a belt sander.

The trigger packs are identical except for a spring-loaded tab on the AUG pack that locks into the rear of their proprietary magazine. Because AR-15 magazines are designed for side latches the NATO stock has several differences from the standard stock:

1. There is no bolt release. The only way to get the bolt forward after it locks back on an empty magazine is to use the cocking slide on the front of the gun.
2. Only the right-side trigger bar reaches all the way to the trigger pack. The other is cut off somewhere before the magazine well.
3. It has a magazine release button, which is actuated by the standard AUG mag release lever. The button is flush with the stock so it probably wasn’t designed to be used directly, but from a shooting posture it is easier to push than the lever behind the magazine.
4. It can’t be adapted to left-hand ejection. Where the standard stock has a rubber cover over a left-hand port the NATO stock is molded solid.

Top: AUG Magazine. Bottom: L5 magazine.

For comparison purposes I have used L5 magazines on the NATO conversion. These cost $13 vs. at least $39 for Steyr’s 30-round AUG magazines. The L5 plastic shell is much thinner than Steyr’s uniformly thick body, but it has metal feed lips and a rubber base to help it survive drops.

My NATO conversion kit had a sticky trigger in addition to an even heavier trigger spring than normal, resulting in a out-of-the-box trigger weight of over 12 pounds (in contrast to the standard AUG trigger of “only” 9 pounds)! Fortunately Steyr has agreed to look at this. I will post details on fixing and improving the trigger soon.

[Update: Steyr’s Alabama technical services group took just two weeks to fix this up beautifully. Now the stock’s trigger is smooth and the sear spring breaks right at 9 pounds. Of course, a 9-pound trigger is still nothing to brag about. See also my post on AUG and MSAR Trigger Improvements.]