One of the biggest advantages Glock has is massive aftermarket support. This ranges from holsters, to spare parts, and magazines. When Magpul announced they were developing the GL9, a PMag for Glock, it was a game changer. To this day, no other pistol receives that level of support. GL9 magazines, while limited strictly to 9mm, come in a variety of sizes. From 10 round ban state mags, to 50 round drums, Magpul has you covered. But how do they perform?
Instead of a plastic body with a steel liner, like Glock factory mags, the GL9 features entirely polymer construction. Because of this, Magpul GL9 magazines are some of the lightest magazines on the market. Their 17 round magazines come in at 1.7oz, putting them a solid ounce lighter than OEM mags. The 21 round GL9 weighs only 2 ounces flat; a full ounce lighter than OEM 19 round options, and as much as 2.6oz lighter than some +5 extensions. Despite this difference in weight, the form factor is familiar. If you've handled a Glock magazine, you have a solid idea of what a GL9 mag is like.
I've found that the GL9 can typically hold one additional round than its stated capacity. However I do not advise shooters overload their mags. That extra round is extremely difficult to load, often resulting in feeding issues, and preventing the magazine from locking in on a closed action.
Be prepared to fully count out your rounds or load to maximum capacity. Magpul includes witness holes at the 10, and maximum round counts, with additional witness holes depending on capacity. To aid shooters in seeing when their magazines are empty, followers are bright orange--something Magpul did before Glock jumped on the bandwagon.
Magpul GL9 magazines were my primary mags for training, USPSA, and range use from mid 2016 to early 2019. They were used during Pistolcraft 1 at Valor Ridge, Haley Strategic D5 Handgun, and Shooter Symposium. Each has 500-1,000 rounds through depending on when it was purchased. Functionally they have been completely reliable with regards to feeding. They have been dropped in dirt and mud, used in the rain and freezing temperatures, and kept in hot cars with no change to reliability.
In the event your magazines become clogged with debris, cleaning is a breeze. Simply depress the large button in the base, then slide the floor plate off. The procedure is the same as a factory magazine, but requires substantially less effort.
Despite the praise, Magpul GL9 magazines are not perfect. They do not always drop free, typically requiring the gun be more vertical for ejection than a factory magazine. GL9 mags are also more difficult to load, resulting in faster fatigue in the hand. I have heard several shooters having issues with durability and reliability in the long term, but I have not seen this first hand.
Once I started exploring aftermarket extensions for factory mags, I decided to perform drop tests before fielding them. While I had used my Magpul GL9 magazines for years by this time, they were included in testing. Parameters are simple. Each magazine is fully loaded, then dropped five times onto concrete from shoulder height. Mags are dropped straight down onto the base plate as though falling from a firing pistol. After five consecutive drops, the Magpul GL9 magazines showed no signs of damage.
Overall I think Magpul GL9 magazines are a solid buy for certain uses. They're inexpensive, reliable, and come in a wide variety of capacities. For someone getting into competition or training and needing to save a few dollars, they're a great option. That being said, GL9 magazines are no longer in my rotation, being replaced by factory magazines with aftermarket extensions attached. The difficulty in loading, along with issues dropping free are my primary reasons for removing them from my lineup. I also would not recommend them for anything outside of training and competition due to reported durability issues. I won't be getting rid of these magazines, but I also don't plan on buying more.
Magpul GL9 magazines are widely available. MSRP varies based upon model, but typically falls between $15-20. You can find them for sale >>HERE<< from Brownells.