With several sports allowing 140mm magazines in their 9mm-friendly divisions, and USPSA’s recent rule change removing round limits for Carry Optics, many competitors are in search of a magazine extension to convert factory magazines to the largest size allowable. Several manufacturers have products available ranging from $24.00 to over $40.00 but not all are created equal.
I’ve been shooting the M&P9 for most of the time it’s been available. I’ve competed primarily in USPSA’s Production and IDPA’s Stock Service Pistol divisions. I did however decide several years ago that it might be fun to get some larger magazines and try Limited/MinorPF with the same gun/ammo. That’s when I found Arredondo’s magazine extensions. These are plastic but well made and quite durable. They claim 23 rounds of 9mm but I can only fit 22 and even then I can’t have one in the chamber without risk of malfunction. For $20 without the spring and $24 with spring, it’s not a bad product at all. It does require some sort of tool to push up the spring plate for disassembly. I bought several more in 2016 (five total) and found I could put 4oz of lead in the bottom of each one, keep using the original mag springs, and run them in Carry Optics to good effect. Unfortunately I discovered this towards the end of the year and after 1/1/2017 USPSA changed the rules for CO to remove the 10-round division magazine limit rendering my setup obsolete. *sigh*
So back to the drawing board. The Arredondo units would work but since I would be removing the weights I wanted to get as many rounds as possible in the mag. Springer Precision has an excellent reputation that is well-deserved. Scott designs and manufactures top-notch accessories and components for many widely-produced guns. His 140mm offering is an excellent choice that holds 23 rounds with one in the chamber. They come in many anodized colors and will work with most magwells, if you are thinking of Limited/Minor. My only problem is that the extension requires a small hex wrench for removal. Even though starting with 24 rounds means the mag will rarely hit the ground, trying to strip and clean these at a match might end with the tiny screw lost, plus you have to keep track of the wrench. Even so, at $35 this is an attractive choice. Also it’s heavier than the Arredondo slightly.
In January 2016 I bought a 170mm extension from Taylor Freelance because I was tired of dropping my stock mags into the snow and slush every time I shot my pistol. This winter I bought another and shot most of the really cold months Open/Minor. I mention this because Taylor Freelance also now makes a 140mm extension. They are well made aluminum units but they attach with a steel retention plate that is held in place by two steel screws at the back of the magazine. This design works well with 170mm unit which holds 28-rounds because it never hits the ground and therefore never needs field stripping. On stages that exceed 28 rounds I’m either not shooting Open or I start with a regular mag, shoot the first array then change to the big stick.
Unfortunately the 23-round 140mm version is far more likely to need cleaning. Much like the Springer units, I see this as a drawback. You would need a wrench to disassemble these, plus steel vs. aluminum doesn’t always end well. At $40 each, this is the second most expensive solution of this type. They also offer a brass unit that is heavier and more expensive.
So after all that, the winner in my contest was Taran Tactical Innovation’s 140mm extension. These are aluminum and very well made and finished. Best of all they have an ingenious solution for disassembly: there’s a sort-of takedown pin that extends through the entire front of the extension, top-to-bottom. When pushed to the up position it retains the extension on the magazine tube and when pushed to the down position, the extension slides rearward and off the tube. This odd setup (normally base pads slide forward and off) is due to the location of the M&Ps palmswell retention “key” at the rear of the grip base. On the Glock version the pin is at the rear.
When I first received the three I bought they were very difficult to get on the tubes. I had to thoroughly clean the lip at the bottom of the mag tubes and really press hard to get the pin to go up fully. After some use they are easier but still require a fair amount of force. This is desirable so that nothing comes loose during use. Using the edge of another mag body works just fine. The pins have detents so as not to get lost also.
These come with extended springs that work perfectly. I have been able to load 23+1 on all three, every single time, with no malfunctions of any kind. I did use new mag tubes since I didn’t want to chance having issues with fatigued feed lips. At $42 each these are the most expensive option but I think in this case it is worth it. Heavy, durable, functional, and handsome (especially that purple!), I’m very pleased with how these run for my CO setup. 2017 should be a great year!