ACCESSORIES: Extended Magazines, Extended Chances

By Warren Wilson
Photo Credit: Cynthia Williams, Cutting Edge Training, LLC
Extended Magazines, Extended Chances
More rounds at your fingertips

Which is better: more or less? In case you haven’t seen the insurance commercial on television, the answer is “more.” This is especially true when discussing defensive ammunition. The humorous saying goes, “The only time you can have too much ammunition is when you’re swimming or on fire.” Considering ambushes against law enforcement, armed encounters with increasing round counts, active shooters, and pharmaceutically enhanced felons, it would seem wise to have every potentially life-saving round at our disposal.

An officer can increase his/her ammunition capacity by carrying more magazines, but there’s not exactly a lot of room left on the modern crime fighter’s duty belt with OC, Taser, radio, pistol, handcuffs (probably two sets) taking up most of the real estate. The street cop can increase cartridge capacity in another way; by purchasing larger magazines that fit the duty pistol or reaching into the aftermarket world for something a little more ‘outside the box’ in the form of a magazine modification. Of course, every potential equipment decision has its drawbacks and advantages.


The magazine is the cause of most stoppages in semi-auto pistols. One thing I’ve learned over the years while dealing with cop equipment is to test it mercilessly before adding it to the trusted duty rotation. It seems that some of us believe just having an item on the belt or in the bag will somehow ward off evil like a modern-day Talisman. In truth, we need well-tested emergency equipment that will perform when we most need it to ward off the tangible evil intending to mean us harm.

Personally, I have had some bad experiences with aftermarket standard and extended capacity magazines. Before getting into law enforcement as a profession, a friend and I bought some 19-round magazines for our Beretta 92s that looked solid on the outside, but did not work reliably with any of the ammunition we tried. We disassembled them to find the strangest clock-type spring we’d ever seen where the familiar rectangular helix compression spring should have been. Those magazines really tainted my opinion for any kind of aftermarket feeding device. They were cheap too and that was yet another red flag we ignored. I swore off aftermarket mags for years after that. In fact, the only aftermarket magazines I’d ever had success with at that point were for the 1911 and the AR15 platforms. Otherwise, it was factory or nothing.

Another consideration is the addition of magazine length. Whether using a factory extended magazine or an aftermarket floor plate, these magazines are about an inch longer than standard. That makes most duty carry and concealed carry impractical. I do not encourage extended mags for primary carry in the duty pistol’s magwell. Where they really belong is in the backup or emergency role.

Another potential negative to be considered are local/state laws and departmental policies regarding extended-capacity magazines and aftermarket accessories that increase your magazine’s capacity. Of course, many of these restrictive state laws offer law enforcement exemptions, but some local laws may grant exceptions only for police duty use and not for competition. Either way, do your research to make sure you’re legal.


Many owners of Glocks and Smith & Wesson M&Ps have discovered the advantage of having a larger capacity magazine as a backup or spare. When carrying a compact or subcompact of these iterations, using a full-size backup magazine as a supplement is both acceptable and advisable. When a full-size pistol isn’t carried off duty, due to extreme weather or clothing restrictions, why not enhance the round count with 15 or 17 rounds of quality duty ammunition on your weak side hip?

For example, those who carry a Glock 17 on duty and a Glock 19 or 27 (the compact and subcompact 9mm versions) off duty are well served by their full-size gun’s 17-round magazine as a spare. The full-size magazines have been found to work just as well in the subcompact and compact pistols, with the unvarying reliability that one would expect from their full-size brethren. The same can be said for the M&P models from Smith & Wesson. I carried an M&P 40 on duty/SWAT for several years and an M&P40c as an off-duty/backup pistol. When carried off duty, that M&P 40c (compact) was always supplemented by a 15-round full-size magazine in an off-side pouch.

Those who carry 1911s have the option of quality 10-round offerings from Wilson Combat or Chip McCormick. My personally owned Smith & Wesson 1911sc Commander sized pistol functions very well with the McCormick10-round magazines. Any of these combinations must, of course, be properly vetted with the exact pistol, magazines and ammunition that will be carried in social situations. If they work, why not have them available?  If they don’t, abandon all folly and go with what you’ve proven to yourself does actually work.

Advantage: Modify

There are also some aftermarket modifications that open up exciting possibilities for increasing your round count. Years after cursing the bad magazine investment for my Beretta, I discovered a company called Arredondo Accessories. They sell a base pad and spring, which increases magazine capacity for Smith & Wesson M&P, Glock and Springfield XD full-size magazines.  The company’s products seem to be geared toward the competitive shooter. I was not confident there would be any practical use for these devices, but I bought one for my M&P 40 duty pistol, mostly as a novelty. The M&P’s standard 15-round magazine was transformed into a 19-rounder. I installed and used the unit during my next few SWAT practices, exercises and qualifications. After several hundred rounds, I did not experience a single stoppage with several hundred 155-grain and 180-grain truncated cone (TC) practice rounds. I decided to give it a real test and add my duty load into the mix: Federal 155-grain HST. Three magazines later, I was convinced that this modification was not just for competition. Since then, I have put several hundred reduced-recoil lead TC reloads and dozens more HST rounds through this pistol/magazine combo with zero issues. During some serious callouts over the last few years, I was confident enough to use the Arredondo extended 19-round modified magazine in my drop leg holster. It was no small comfort having a reliable 20-round pistol at the ready when serving my rotation on the immediate action team.

Always the pessimist, I was certain that there was no way this magazine would work with my 3.5-inch barrel M&P40c. There’s a “window of operation” that exists between magazine spring tension, recoil spring strength, the length of the slide, and a whole myriad of other factors that choreographs the delicate ballet known as internal ballistics. Simply put, shorter autos generally suffer in reliability more so than full-size guns when any elements of the equation become less than perfect. The thought of carrying 30 rounds of .40 caliber ammunition off duty on my person was too enticing. It was time to burn some more powder. Remarkably, the Arredondo-enhanced M&P magazine functioned perfectly in the compact pistol with Federal practice rounds, Federal HST and Corbon 150-grain ammunition. During hot weather months, my off-duty battery became the M&P40c backed up by a 19-round Arredondo enhanced Smith & Wesson magazine.

Regardless of the current success, I was certain that at some point, my much-anticipated disappointment would arrive as it usually does when things seems too good to be true. With what could only be described as an incredulous confidence, the next test subject would be a Generation 3 Glock model 20, chambered for the 10mm cartridge. This combination would be especially interesting for any potential outdoor setting, if it would actually work reliably. The Arredondo base pad for this model added five rounds to the Glock’s full-size 10mm standard 15-round capacity. Imagine 21 rounds of 10mm in any of its power configurations for defense against predators in any of their nefarious configurations. Be they two legged or four legged, the 10mm shines against all but the greatest of beasts. This magazine setup was tested with several boxes of 150-grain Corbon Original JHPs and 175-grain Winchester Silvertips with 100 percent reliability. As with the other pistols tested, the chamber was loaded and then the magazine topped off and re-seated, just as it would be carried or loaded in an emergency situation. Still, the drama of a jam was elusive, even after 100 rounds fired.

I thought that perhaps longevity must be the fatal flaw for these systems. But no, it turns out that Arredondo uses quality parts from Wolff Gunsprings. What would it take to pull the lever on the gallows of my disappointment? It struck me that the experiment was over and these magazine extensions just plain worked and proved themselves ready to serve as emergency magazines.

Saving the best for last, one manufacturer of fine defensive pistols offers a 33-round factory magazine for their 9mm pistols. I’m speaking of Glock, Inc. and this mag and the Austrian maker’s 29-round .40-caliber magazines have a solid reputation for reliability. Personally, I like the idea of having one or two of these in the glove box or my duty bag. Hopefully, the other manufacturers will someday offer similar Über-mags for their pistols.

So What to Do?

I’ve become a believer in having the most rounds and largest magazines available as is practical, legal and consistent with department policy. Shooting debriefs from around the country inform us that we see more bad guys acting as bullet sponges. High round count encounters involving police occur more frequently. Videos released of law enforcement shootings show violent felons using basic tactics against us, which contributes to the lengthening of armed encounters and further endangers our fellow police officers. As the nefarious evolve, so must we. Consider the possibility of higher capacity magazines for both your on-duty and off-duty missions. Here’s praying you never need them.  PM

Warren Wilson is a Lieutenant with the Enid Police Department in Oklahoma.  He is a former SWAT team member/leader and has been in law enforcement for 17 years..

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