I get it, but have never seen ANY VZ 58 mag tests online and I've watched many videos...
That's because most people use the relatively cheap VZ58 surplus mags.
But let's take a look at their own blurb. It was obviously written by the marketing department.
"The AC-Unity 30rd 7.62x39mm window magazine for your Czech model VZ58, VZ2008 or other clone that use VZ58 magazines. Designed to offer greater strength and impact resistance than original VZ58 aluminum magazines.
Made from an advanced, German made polymer-resin/granulate that is light weight and extremely shock resistant. The body is impact resistant through a wide range of temperatures (-30°C to 120°C.). This polymer is exclusive to AC-Unity and gives these mags a huge edge in weight and durability.
Front and rear locking lugs and reinforcements are machined from German GD ZN 410 metal legure; this is a specific German marine grade metal-alloy that is hardened, anti-magnetic, highly anti-corrosive with great wear properties.
Carbon wire spring has a lifetime warranty against corrosion and will not degrade from use or loaded storage. These are designed for long term storage, even when fully loaded.
Low-friction anti-tilt follower and a removable floor plate for easy cleaning.
This mag is built to last using state of the art materials! AC-Unity magazines are used by Bosnian Defense Forces and other militaries in Europe and the Middle East. Not just military grade; but current military issue.
Lifetime warranty against defect, loss of spring strength or corrosion.
Specifications:
Magazine Weight (Unloaded): 6.0 ounces
Color: Black
Capacity: 30rd
Cartridge: 7.62x39mm
Condition: New
Production: Made in Bosnia and Herzegovina"
So...
It has ribs and won't dent. (That's what they mean by "impact resistant"). The "polymer-resin/granulate" is probably a form of nylon or whatever else they are making glock frames from these days, with a healthy handful of fiberglass, carbon fiber, or nano-robots for all I know.
GD ZN 410 is the fancy name for Zamak 5, which is a fancy name for zinc alloy, which is what most people call it when they are trying to be nice. RSR would probably just call it 'pot metal.'
It has many properties that make it an ideal material. It can be cast to very close tolerances, minimizing machining time. When coated, it is impervious to the elements. If the coating is breached, by say, cartridges passing though the feed lips? Or by a magazine well on the outside of the magazine? Then you will get corrosion over time. Another property of zinc is that it is brittle, compared to aluminum or steel. A sharp enough and heavy enough shock in the right spot can crack it, especially if corrosion has gotten to it.
Carbon steel spring, probably coated. Designed for "long term storage," interesting choice of words there. "Low friction" (AKA "plastic") floorplate and follower.
Used by "Bosnian Defense Forces" and made in Bosnia as well.
All of this tells us quite a bit. These were made by the lowest bidder or by a relative or friend to someone in power in Bosnia, to presumably, the Bosnian military. The military is going to say "we need XX million or thousand magazines. They have to be able to sit on a shelf for a long time and still be good. It has to not break when it's tossed in with a bunch of equipment. It has to survive X number of reloads before disposal or refurbishment."
That number is probably between 5 and 20. It is the soda can, wrapped around 30 fluid ounces of liquid 7.62x39mm goodness. In the eyes of the military, once that goodness is gone, you throw away the can or recycle it. The armorer checks it, gives the spring a push to test it, and out it goes again to the field, refilled. It's the disposable bit of the rifle, and that is how the military views it. If the military doesn't view it that way, the soldiers certainly do.
I would consider this magazine to be ideal for storage. I would consider it to be absolutely reliable for the first five magazine loads through it. I would start checking the feed lips for cracks after that, most likely completely unnecessary, but I'd probably still do it just the same. I would use these and save my aluminum surplus mags for when reliability and durability absolutely mattered.
