AR and Pistol Mag Test Proves Long-Term Spring Functionality

Article by Paul Ivnitskiy and David Lewis of AmmunitionToGo.com
As you know, if your magazine spring loses its elasticity or breaks, it can render your firearm almost worthless. AmmunitionToGo.com conducted a test to determine how long mag springs can last. The test also examined whether leaving a mag loaded for an extended period of time causes problems, or if loading a mag can damage its spring. The test findings are eye-opening and show that, under controlled conditions, the springs themselves will last more than a human lifetime for most shooters.

The test crew subjected 13 different mags (from multiple manufacturers) to a test protocol over a year. The protocol included loading and unloading to full and half capacity, storing in climate-controlled and fluctuating temperatures, and storing in a non-climate controlled shed.

READ FULL TEST REPORT with 13 Magazine Results, Charts, and Photos »

Field Testing — Magazines Performed Flawlessly
The crew took the mags to the range for field testing throughout the test study. The results revealed that regardless of the frequency of loading or unloading, or storage conditions, not a single magazine failed. The use of a digital force gauge showed no significant variability in the springs’ resistance from mag to mag but all the tested springs put up 20-25% less resistance than when they were fresh out of their factory packaging. That said, all of the mags performed flawlessly during field testing.

Laboratory Magazine Testing — Tens of Thousands of Cycles
To determine precisely how much punishment a mag can tolerate before its spring starts wearing out, the team recruited help from lab technicians at Applied Technical Services. The results showed that a factory Glock 17 mag spring endured 14,842 cycles (the equivalent of 252,314 rounds) before it snapped, while the Magpul Gen 3 PMAG endured 69,881 cycles (2,096,430 rounds) before it finally gave up.

While this testing was not perfectly emulated under real-world conditions, it is safe to conclude that mag springs are remarkably durable. Many believe that by downloading a mag, that is, loading the mag shy of full capacity, they can protect their mag springs. However, the real world trials don’t offer up any evidence to support this kind of behavior by shooters.

Conclusion — Get Good Mags and Don’t Worry About Them
Common wear and tear from everyday use is more likely to degrade the overall quality of a firearm magazine than the spring failing on its own from being loaded to full capacity and stored for long periods of time. So, unless you’re part of the group of individuals that actually shoots thousands of rounds down range on a weekly basis for training or completion reasons, the whole issue of worrying about the lifespan of your magazine springs is somewhat trivial.

Other Important Factors to Consider
There are many other factors to consider before worrying about magazine spring failure. First, address the overall quality and cleanliness of your firearm, magazine housing, guide rod, buffer tube spring, ammunition choice, the list goes on. Magazine springs are relatively cheap items that can ultimately fail, just like any other man-made item before it. Luckily, magazine springs are very easy to replace once identified as the cause of a malfunction.