Why do magazines curl?  Can someone point me to a thread?
Is it so you can lay down with them easier?

It would be kinda cool for a 100 round straight AR mag

Quoted: It would be kinda cool for a 100 round straight AR mag

Yeah!  A mag that doubles as a monopod!

ahh...  thanks very much.
I guess the effect isn't really a problem with the first /last 10 rounds in the magazine.  That's why that part can be straight.

Lay 30rd of 7.62x39 and you'll see why the AK mags are bent even more. Also look at .223 Ak mags - they're much straighter. It's all because of the case taper (mainly) to allow proper feeding.

heh.. I actually just saw someone using a magazine as a monopod on the history channel.

FWIW, the curve of an AR magazine doesn't follow the "rounds in a stack" exactly because of the AR's mag well.

The original design for the 30rd mag was fully curved like a .223 AK mag but wouldn't fit in some M16 mag wells, thus the straight-then-curved shape.

I'm calling



We have USGI, HK, FAL & other 20 rounders in 7.62 & 5.56 that are straight. IIRC HK made a Straight 30 rounder too. It makes sense to curve it to make it less obtrusive while maneuvering the rifle. Also as someone pointed out, the USGI 30s have a straight design to accomodate the mag well.

The rounds stack farther down the mag with progressively nosed up angle due to the taper of the case.  With the straight 20 rnd mags this is tolerable, but the cartridges have to slid against each other as they feed up into the well and into the chamber.

If the mag were long enough, the cartridges and follower would have enough tilt to cause problems, thus the curve of the 30 and larger mags.

The AK mag has a more pronounced curve due to the greater case taper.

I once had some 30 rnd Mini-14 mags from Mitchell Arms that just would not feed.  You could not fire more than 7 or 8 rounds without a misfeed.  The cartridges would begin to come up tail low.  No amount of adjusting the feedlips would cure the problem.

Finally, I happened to place the Mitchell mag directly on top of a Federal Ordnance (later PMI) mag.  The curvature of the Mitchell was MUCH greater than the Fed Ord mag.  This was the cause of the rounds coming up tail low and not feeding.

Note that even with the old straight M16 mags, the floorplate was angled sharply.  This was needed to keep the rounds from feeding nose low.

The USGI 30 is a compromise between the straight section and the curved section.  If it were possible to make it completely curved, of the correct radius, it would feed smoother, and the anti-tilt follower would not be required.

Another way to make a doublestack mag feed with less curvature is to have a fore-aft taper, the front of the mag being narrower than the rear of the mag... and you will see some mags like this, too.

wow...  great answer.. ty

Quoted: heh.. I actually just saw someone using a magazine as a monopod on the history channel.

You guys don't use it like that from prone?  You guys are missing out.  I tell most of our soldiers to do that when qualifying, and it works.