A Svelte 15rds: Shield Arms Magazine Catch and Magazines for Slim Glocks

When it comes to personal defense my primary concern is accurate shot placement, control, and wound potential. Most of my personal defense firearms have an eight to fifteen round capacity. A compact handgun that holds ten rounds of 9mm Luger but has a small footprint and is easy to conceal is attractive.


The Glock 43 was a long waited slimline 9mm, Glock’s first. Glock more recently introduced the Glock 43X and Glock 48. Each features ten round magazines. This is possible as the 43X has a longer grip frame than the Glock 43. These are typical Glock magazines in design with a polymer shield covering a steel inner structure. The Glock 43 is a very reliable handgun. On that basis I am reluctant to modify the Glock or any other reliable handgun with aftermarket parts.

After a considerable test and evaluation I find the Shield Arms conversion magazines a viable upgrade for those wishing to have greater magazine capacity. Magazine capacity isn’t everything but in this case it seems well worthwhile to upgrade the pistol. Shieldarms.com 

The Shield 15 round magazines are well designed and executed. The magazines are steel magazines with a modest base pad. These magazines are designed to hold fifteen rounds of 9mm Luger ammunition. This makes for a 50% greater reserve of ammunition. This capacity really adds up. A pistol and a spare magazine now means thirty rounds of ammunition rather than twenty. If two spares are carried the total load is forty five rounds rather than thirty.

This is a considerable boost in reserve. I don’t foresee needing that much ammunition but it is better to have it and not need it than the opposite, and I always carry a spare magazine. The Shield magazine fits the Glock 43X or the Glock 48 grip frame. Function is good. However Shield Arms recommends that the standard polymer magazine catch be replaced with a metal magazine catch. A steel magazine rubbing against a polymer magazine catch isn’t ideal. The magazine catch is properly designed and dimensioned and is a straight up drop in modification to the Glock 43X. By measurement the steel magazines are about .005 wider than Glock magazines. 

To install the magazine catch first clear the pistol and be certain it isn’t loaded. Field strip the pistol normally. Lay the slide aside.  Looking toward the magazine catch in the frame, looking from above, it is best to use a light. 

There is a tensioned spring in the magazine well that holds the magazine catch and provides power for the magazine catch to return to position after pressing the magazine catch to release the magazine. A long hooked tool works well to move the spring aside. The spring is picked up and out of its notch in the magazine catch. Then you roll the catch out- or wriggle it out to one side.  The Shield Arms magazine catch is aluminum rather than polymer. The fit is exact. The magazine catch easily fits into the Glock frame.  Replacing the wire spring is simple enough however sometimes takes a bit of play to get the spring locked back in place. You may actually pull the wire spring out of place and later replace it. I think that with the small frame gun removing the spring is easiest. The new metal latch isn’t an extended type, all to the good when wearing a pistol concealed and close to the body. The Shield Arms magazine catch is well designed and positive in operation. 

With DeSantis Slim Tuk

I had on hand several Shield Arms magazines. Some high capacity magazines are difficult to load to full capacity. It is good to have a strong spring but not good to have difficulty loading the last few rounds. All magazines were loaded without difficulty, just a firm push to finish up loading. I did find that when loaded to full capacity a firm slap is needed to fully seat them if the slide is at rest, not unusual.

My recommendation is to load the magazines to fifteen rounds and then lock the slide back before loading the pistol. Insert the magazine firmly home then drop the magazine. I loaded and unloaded the magazines in the pistol and found that all locked in place in a positive manner. Original Glock ten round magazines still function but require more effort to remove they do not drop free. This isn’t a important as the shooter will be deploying fifteen round steel magazines. 

I have test fired the Shield Arms magazines with a variety of ammunition. I was careful to be certain the feed angle is still good for jacketed hollow point ammunition. It is important to be certain the magazines are firmly seated. I find the Shield Arms magazines and magazine catch reliable and a viable upgrade to the Glock 43 X pistol.