How to Expand S&W M&P Shield Capacity

S&W M&P Shield capacity expanded with MagGuts kit.

The S&W M&P Shield was the king of single-stack 9mm pistols for a long time. It held that position for good reason. The Shield is reliable, small, very shootable, and the price of the gun is unbelievable. In the past few years, other guns have challenged the Shield by using a staggered magazine to hold more rounds, thereby increasing the capacity that a small gun can hold. But your Shield isn’t obsolete just because another gun shows up that holds more bullets. Instead of heading out to buy a new gun, you can just as easily (well, more easily) expand the capacity of your M&P Shield 9mm magazine. Let’s take a look at several ways you can expand your Shield’s capacity as well as ways to improve your personal safety.

3 Ways to Expand S&W M&P Shield Capacity

1. Extended Magazines

Probably the easiest way to expand your Shield’s capacity is with a higher capacity magazine. The concept is an easy one. Just like the factory 8-round 9mm Shield mag is longer than the flush-fitting 7-round mag, extended magazines are longer to increase capacity.

A perfect example is the ProMag 10 round Shield magazine. The additional 2 rounds are gained by extending the length of the single stack magazine.

Expand S&W M&P Shield capacity with a longer magazine like the ProMag 10-round mag.

If a longer magazine is an option for you, the ProMag 10 round magazine provides a +2 option for increasing the capacity of your m&p shield 9mm magazine.

The advantage of this approach is that it is plug and play. Simply make the purchase, load it up and insert it into the gun and you have moved from an 8+1 configuration to a 10+1 set up. In my opinion, the biggest drawback is that you have significantly increased the grip-length of the gun. This can change the balance of the gun and more importantly, make concealment more difficult.

2. Extended Basepads

Extended base pads are another way to expand the S&W M&P Shield capacity. They have the same disadvantages as extended magazines as they can change the balance of the gun. They also have an additional negative point in that they can require tools to install. GMW has Tyrant Designs extendos in stock (yes we sell them and we’re talking about them, because capitalism). Use of extensions like this is becoming increasingly common if not ubiquitous.

S&W Shield 9mm magazine

A magazine extension can provide a number of benefits, but it does make the mag bigger.


M&P Shield 9mm magazine extensions from Tyrant CNC.

Tyrant CNC’s mag extensions require no tools to install and add +2 rounds to the magazine’s existing capacity. And since these base pads are available in a variety of colors, you can customize the look of your mag and your gun — which is a big plus for some folks

3. MagGuts Magazine Internals

If the Shield is the gun for you and you want to increase its capacity without increasing the overall size of the gun, the most elegant way I know to accomplish this goal is with MagGuts.

Expand S&W M&P Shield capacity with MagGuts.

MagGuts increase S&W M&P Shield capacity and allow for the use of the factory base plate and sleeve or the MagFIX like I use. Either one keeps your mag exactly the same size as when it started.

MagGuts is a product that replaces the factory spring and follower in the Shield’s magazine. The flat metal z-fold spring and lower-profile follower take up less space inside the magazine, to allow one more round in the magazine. So now you can squeeze 9 rounds into your 8-round magazine. That’s an increase of 10% with no external changes in dimension.

Want to expand your Shield's capacity? Try MagGuts - A significant amount of space is gained by simply streamlining the follower.

A significant amount of space is gained by simply streamlining the follower.

When I carry my Shield I carry it with the MagGuts installed in my 7-round, flush-fitting magazine. It adds an additional round there while giving me a small, thin, 8+1 pistol. I carry a spare extended mag in my pocket with the MagFIX base pad and a MugGuts kit for a 9-round reload.


Ways to Improve Your Personal Safety

Reduce your need for more bullets

I think that this underutilized strategy has more payoff potential than any other strategy. The concept is simple. If you reduce your need to use a gun, you significantly reduce the need for more bullets. What I’m talking about here is taking active measures in your life to reduce the likelihood that you will need to defend yourself or those that you love with your gun — or any other tool.


Spend some time considering what you can do to reduce your risk profile. By doing so, you not only reduce the need for a higher capacity gun, but you also reduce the risk that you will face all of the other negative outcomes that can be associated with a violent encounter. If you avoid getting into a gunfight, you avoid injury and death. You also avoid making a mistake that takes the life of an innocent person or that lands you in criminal or civil legal issues.

If you haven’t invested in avoidance you aren’t getting the most juice out of the squeeze.

Examples of Avoidance

When you are relaxing at home, are your doors locked? Do you scan transitional spaces before you enter them? Are your vehicle doors locked when you are in your car? Do they stay locked until you intentionally unlock them?

Consider where you spend time, when you spend time there, and who you spend time with. Is it possible that better choices in this area could reduce your risk? Also, think about the non-verbal signals you send when you are out and about. Do you convey that you are a confident and competent individual that isn’t worth messing with? Or do you appear to be the victim that a criminal is searching for?

Carry a Larger Gun

I love my Shield, but I rarely carry it. I am one of the lucky ones that get to choose how I dress. That means carrying a larger gun is easy for me. Interestingly, I routinely conceal a full-size gun under an untucked shirt, so I don’t dress significantly different from most middle-aged men. With the right combination of holster, gun, and person, I think most men can easily upsize their pistol.

In my opinion, smaller guns are not always easier to carry and conceal. The larger size and thickness of a full-size M&P 9mm isn’t that much more difficult to conceal, and there is no way you can turn the 8+1 Shield into a 17+1 M&P. Translate that to Glock or Sig or Springfield and the result is the same. If you really feel like you need more capacity, consider carrying more gun.

Final Thoughts

I think that most of us, with the right holster, can carry more gun than we think we can. I also think we can reduce our risk of ever needing a gun through thoughtful changes in behavior. Of course, we can never guarantee we won’t need a defensive handgun. That is why we carry and why we should carry.

When your pistol needs to be a Shield and you want some more capacity, consider extended mags, extended base pads, and the MagGuts. Make the decision that is best for you, test it out and then carry on.

The MagGuts kit for the Shield uses a metal follower to help increase the available space inside the magazine.

The MagGuts kit for the Shield uses a metal follower to help increase the available space inside the magazine.


Paul Carlson: read more of his articles.

Extendos: learn more about extended magazines.

M&P Shield: see what else we’ve written about.

Paul Carlson, owner of Safety Solutions Academy, is a Professional Defensive Shooting Instructor.  He has spent the past decade and a half studying how humans can perform more efficiently in violent confrontations and honing his skills as an instructor both in the classroom and on the range.

Through Safety Solutions Academy, Paul teaches a variety of Critical Defensive Skills courses in more than a dozen states annually.  Courses range from Concealed Carry Classes to Advanced Critical Defensive Handgun Courses and include instruction for the defensive use of handguns, rifles and shotguns.  Safety Solutions Academy regularly hosts other industry leading experts as guest instructors to make sure that SSA’s students have the opportunity for quality instruction across a broad range of Critical Defensive disciplines.

  • GA Hoffmann

    Magguts makes a +2 now, which will up the capacity of the 7 round mag to 9 with very little, maybe ¼ inch, increase in length. The same kit will also fit the 8 round mag and give you 10 +1.

  • GomeznSA

    Or you could just carry the Shield in .45 😉
    Really like my Performance Center Shield 9 and have been looking at MagGuts, sill most likely invest in some in the near future.

  • Ian Wolfe

    Personally, I have found that using the Wolff +P springs made an immediate and noticeable improvement in mag reliability, especially when using the extended base plates. For the money, those springs have been the best aftermarket improvement I have made to my Shield.

    • Paul Carlson

      Wolff makes good stuff.

  • 2ThinkN_Do2

    Personally, you could just say, 8 is enough (sounds like a TV Show name?) and live with it. Though I do like the mag extension base pad to some degree. Or if you’re that set on needing more rounds, carry an extra spare mag. If you want to have more than 16, carry two extras. I carry 2 extras with any firearm less than 10 rounds per mag.

    • Skip Wilson

      I have been Quite Happy with my 10 round SR9c But in my Texas Holdem Shoulder Holster it carries 3 extra 17 round SR9 Mags

  • Blumpkin

    What happened to the safety solutions plan b?

    • Paul Carlson

      It became polymer and is now called the MagFIX. Better performing, less expensive. BUT it doesn’t increase the capacity so I didn’t include it as a solution in the article. I did in the pictures though! is where you can find it.

  • disqus_P75F1IQr1N

    Lots of excellent points, but I can’t quite agree with this one: “. . . [T]here is no way you can turn the 8+1 Shield into a 17+1 M&P. Translate that to Glock or Sig or Springfield and the result is the same.” A SIG P365 is about identical dimensionally to a PPK (but much lighter) with 10+1 rounds. Add an extended mag and you have a 1″ taller (but still lighter and still quite concealable) PPK with the capacity of the [cereal-box sized] M9. It isn’t magic, but it sure seems that way.

    • Paul Carlson

      Absolutely, but for someone that right now has a Shield and wants more capacity these are some options. Buying a new gun might not be.

      • disqus_P75F1IQr1N

        Sorry, I was responding to what appeared to be an assertion that my SIG shared the same limitation as the Shield. If I misunderstood your intent, I apologize.

        • Paul Carlson

          No need to apologize. All I meant was you can’t make a single stack into a double stack and I would even say a p365 is t ever gonna be a p320. It is closer than a shield is, but small guns and full size guns are different.

          • disqus_P75F1IQr1N

            “I would even say a p365 isn’t ever gonna be a p320.” Well, I’ll agree with you there: the P365 has a better trigger, lower bore axis, and more caliber-proportional slide width and grip size (one could add a more hand-filling grip frame to the P365, but can’t slim the .40-size ribbed P320 mag).

            Some disparage SIG for introducing the P365 to “compete” with its own P320SC, but IMHO the exact converse is true: the real shame is that the military contract commits SIG to mass-producing the lesser of its own two pistols for the foreseeable future, reducing the likelihood it’ll scale up the more evolved P365 to service size.

  • Closet Warrior

    Buying a brand new gun you have to work on to satisfy your bullet count seems rediculous to me. I do this crazy thing called buying a gun that have standard higher capacity magazines, carry a spare mag and done. Most gunfights are just a few average shots fired anyway. I would carry an ankle gun too if I were that worried about bullet envy before tearing into my collection. All I do is shoot, clean, repeat.

    • George Heidke Sr

      Totally agree !!! I see no reason to buy a small gun……….then try to make into something it is not !!!

      • Closet Warrior

        Exactly and articles like this one could get someone hurt or killed. I hear tell of many DIY magazine mods such as feed issues…bad news in a self defense situation.

        • Paul Carlson

          You might also reread the part of the article titled, Ways to Improve your Personal Safety. It is there specifically to highlight the idea that there may be better ways to stay safe than modifying your Shield.

          • Closet Warrior

            Being mindful of your surroundings and avoidance of confrontation is totally different than gunsmithing. BTW, I carry a lower capacity compact in warmer months and I keep 15 rnd mags in my pocket that do fit and work well w/my weapon but I will not say what companies because the people reading these posts may do what I say and have failure due to my suggestions…you pickin up what I’m puttin down? Safety and Responsibility falls in the hand of only those who are just that.

          • George Heidke Sr

            30 short years ago, PD’s only carried revolvers, we came a long way in short order to having very dependable semi-autos at super reasonable prices. That said, our society has changed too & where you live is a major factor in deciding what you carry.
            I live rural & if involved in an unfortunate incident, I would need barrier blind ammo & way more than a low capacity pocket gun. In today’s world, you will be more likely to be involved with a meth-head, & a few shots just ain’t gonna do it for you.

          • Closet Warrior

            True, other weapons aside, since we’re talking about low capacity compact semi-auto pistols. I’m in the same boat, rural area, close neighbors and many meth-heads and needle jockies abound, so I top off 3 rnds of my mags w/frangible ammo as not to shoot thru my walls and kill my dad next door or a neighbor. Another barrier is that I live 40 feet from a major highway, lots of interesting moments I promise but If I’m caught in a fight or flight situation w/said junkies or travelers w/a handguna and I’m in my yard away from my shotgun or ARs then the best course of action would be a well placed headshot or two to best remedy the out-of-hand situation. After all, it’s your life or theirs, self-protecing and well within the boundaries of the law. Also, funerals are cheaper than hospital bills.

          • George Heidke Sr

            Where I live the closest neighbor is a mile away. Police would take a 1/2 hr or more to reach me.
            When they do……..there will be only one side of the story to hear.

          • Closet Warrior

            Well, that’s less lies and bullshit you and the officers will have to listen to and discern for the debriefing. Like you said…it would probably be a meth-head and they are far from extinct. You’d probably fare pretty well. Self-defense n all.

    • Paul Carlson

      This article isn’t for you Closet Warrior and it isn’t for me. I carry full size gun daily. It is for the person that already owns a Shield and maybe nothing else that right now is feeling like they want more rounds and doesn’t even have the option to go out and buy a new gun because of availability or lack of funds.

      I hope that makes sense.

      • Closet Warrior

        I think I can comprehend…you think all Shield owners have the cranial fortitude to successfully navigate the firearms industry in a gunsmithing manner that could plus size their magazines w/out any catastrophic failure or feed issues during a deadly conflict… 100% guaranteeing that all your readers are potentially safe? I don’t wanna get into a pissing contest, I just think it would be safer if you told both sides of DIY mechanics. No hard feelings, you have a potent platform and need to be mindful as such.

        • Paul Carlson

          there is nothing that is a 100% guarantee and I can never change that…

          What I can do is take your point to heart. There should have been a part of the article that discussed reliability testing of diy gun work.

          I will do an entire article on that. I agree, no hard feelings. Sometimes, we assume the things we know in our heads are known by everyone… not true.

          • Closet Warrior

            Thank you, I look forward to it. I’m not a ballbuster just had some close calls w/good ol boys modifying pistol mags that now don 4 fingers at the range w/a story to tell. We appreciate these pro 2A platforms, so thank you and always be mindful of all your potential surroundings both real world and digitally. Have a safe productive day.

  • Military Arms Channel

    I converted two Shield magazines using the MagGuts conversion and both have reliability issues so I gave up on that option.

    • Norseman65

      Thanks for the info on that!

    • Skip Wilson

      i Trust Anything that Tim puts Out there

      • Closet Warrior

        Wanna buy some prime swamp property in Florida? Really, you trust his every word, re-read some of his and mine posts. You may want to wait for the revised article before you go blindly trusting a person of influence, sound familiar…ughemm (government),(Fox news), fearless leader who is doing worse than nothing. Spreading lies amongst a global pandemic that will just magically disappear? WTF…you need to think for yourself or all disinformation turns to truth.

    • Paul Carlson

      Tim – Gen 1 or gen 2 Magguts? Did anyone else test your mags before you touched them with your wrecking ball hands? 😉

    • GA Hoffmann

      I’ve installed two magguts +2 spring kits and one +1 spring kit on 3 of my Shield mags. I Have at least a thousand rounds total through the 3 of them without a malfunction.

  • Regis

    I did the +2 and barely any difference in carrying

  • George Heidke Sr

    I can’t believe you recomended a a Pro Mag ……..really !!! We’re talking life & death personal saftey, arn’t we ????

    • 2ThinkN_Do2

      I bought some of those branded mags long ago, 2 out of 3 had issues with loading and or feeding. I was luckily able to fix the issues and make them reliable. However, one should not have to fix something they buy that is brand new. I won’t buy them ever again as a result. PS – it was not for a Shield, nor was it 9mm.

    • Paul Carlson

      Recommend is a strong word for what I did. You might notice that I ended that section on a disadvantage. I offered an option.

  • Closet Warrior

    Being mindful of your surroundings and avoidance of confrontation is totally different than gunsmithing, Is it me or is this article about safety or S&W Shield publicity?