Best SIG P320 Conversion Kits – 2021 Top Picks Reviewed

| Last Updated: September 4, 2021

Shooting a variety of different calibers is one of the most fun parts about the shooting sports. Unfortunately, that usually means a different firearm for each one.

However, some guns are modular. In other words, they can have a few parts swapped out that enable them to safely fire a different caliber. The SIG P320 is one of them. Swapping in new parts using a conversion kit allows shooters to easily change up their handgun caliber.

Scroll down to check out some of the best SIG P320 conversion kits on the market today.

Comparison of the Best SIG P320 Conversion Kits

IMAGEPRODUCT
  • High-quality components.
  • Best P320 conversion kit for the money.
  • Great for converting your pistol to a compact size.
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  • Easy to install design.
  • Made from high-quality materials.
  • Easy to attach to most P320 pistols.
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  • It offers enhanced accuracy.
  • Fits most P320 conversion kits
  • Made from high-quality materials.
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What to Watch For When Buying a SIG P320 Conversion Kit

Anytime you are in search of new gun parts or conversion kits, it pays to be well informed. The following tips and information will help you on your quest to find the ideal SIG P320 conversion kits for your needs. 

A Veritable Arsenal

The amount of conversion kit caliber options for the SIG P320 pistol are impressive. This modular pistol can be chambered in and switched between 9x19mm Parabellum, .357 SIG, .40 S&W, or .45 ACP calibers. This allows for a great variety of choices and should keep most shooters busy for a while.

More Than Calibers

The SIG P320 is modular in more ways than caliber changes. It can also be converted into different pistol sizes. This adds greatly to the versatility of this firearm. Having the ability to change the frame size allows it to adapt to specific scenarios such as concealed carry and competition shooting. The P320 can be converted into the following frame sizes: carry, sub-compact, compact, and full-size.

Having the ability to go from a full-size .45 ACP to a sub-compact 9x19mm Parabellum via the same platform is an impressive feat. The SIG P320 is known as the most modular handgun on the market today for good reason.

Understanding Installation

Changing calibers and frame sizes might sound like an intimidating process to shooters with minimal gunsmithing skills or knowledge. However, these changes are fairly simple for just about anyone to successfully carry out. In other words, if you can disassemble your SIG P320, you can also correctly utilize these conversion kits. It really is just a matter of fitting the P320 fire control group into the conversion kit parts and putting the gun back together.

CAA Micro Conversion Kit (MCK Stabilizer) Sig Sauer P320

Stepping it Up

Changing up the caliber or frame size isn’t the only conversion option for SIG P320 owners. Also available are conversion kits that turn the SIG P320 into a semi-automatic carbine. These options typically don’t even require any disassembly of the pistol. You simply drop the pistol in and lock it in place. 

There is plenty of room for accessories with multiple Picatinny rails and a shoulder brace for comfortable and steady shooting. These types of conversion kits can be a lot of fun to use on the range and add an entirely new dimension to shooting your SIG P320. Just make sure to check your local laws and regulations to ensure that they are legal to own and use in your area.

Review of the Best SIG P320 Conversion Kits

Below is a list of the five best SIG P320 Conversion Kits currently on the market. As you look through each one, it is important to make a note of what’s included along with some other features and characteristics that you believe are interesting to you.

Once you find one that is considered the best match for you, you can buy it and give it a try for yourself. Now, let’s unveil our “best overall” P320 Conversion Kit:

Best Overall

Sig Sauer – Caliber X-change Kit Sig Sauer P320 Compact

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What Recent Buyers Report

Most recent buyers were looking to turn their P320 pistols into a more compact, concealable version of the pistol itself. They managed to easily make it convertible from a full-size to the compact size in a matter of minutes. One user said that he had to convert to a compact size because carrying a full-size was too uncomfortable for him.

What Recent Buyers Report

Now we turn our attention to the size down from full-size. We consider this one of the best sizes for your P320 if your main goal is to make it as concealable as possible all while not making it too small for your hands. Of course, it includes all the fixings like your slide, grip module, and a magazine that can hold up to 15 rounds.

Who Will Use This Most

This will be a conversion kit that will get the attention of many every day carry users. Especially when they might be having a concealability issue with a full-sized pistol. It might be easier for them to convert to a smaller size without having to blame either the holster or purchase a new pistol that might be even more expensive.

What Could Be Improved and Why

The magazine can use a little size reduction so it’s not too tight or too loose of a fit in the mag well. You want it to be reliable enough to feed your chamber the shots you want to fire off. Too tight of a fit might complicate that.

Bottom Line

If you’re looking for an excellent conversion kit that will turn any P320 pistol into a compact size, this Sig Sauer conversion kit might be the answer. Nothing makes a P320 more concealable and out of plain sight better than a compact size.

Pros

Great For EDC Carry

Affordable For Most Budgets

Great For Better Concealability

The Grip is Nice and Sturdy For Most Hand Sizes

Easily Convert a Full-Sized Pistol Into a Compact Pistol

Cons

Some Fitting May Be Required

Installation May Be a Challenge For Some

The Magazine Might Be a Little Too Tight of a Fit

Runner-up

CAA Micro Conversion Kit (MCK Stabilizer) Sig Sauer P320

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What Recent Buyers Report

Most recent buyers were concealed carry users or use their P320 for tactical or occupational reasons (i.e.–police and military). They were satisfied with how quick and easy it was for them to convert their pistols into a decent size that was great for concealability. They also were satisfied with the overall rugged design.

What Recent Buyers Report

This conversion kit is considered to be one of the best on the market when it comes to fast assembly or disassembly. Either way, you slice it, you’ll be able to put this to good use in a matter of minutes. Once you have it installed, it will be ready for battle no matter which application you use your P320 for.

Who Will Use This Most

This will likely be a favorite among the government agents and law enforcement personnel. It will also be a great kit that is useful for your regular concealed carry user. No matter who uses it, they’ll get a kit that is simple to use and makes the P320 much more usable and concealable.

What Could Be Improved and Why

A possible improvement that can be done is including a grip module that will work nicely with this conversion kit. This kind of kit takes care of the barrel part of your P320 pistol. Looking at this and seeing no pistol grip module, it looks a little incomplete.

Bottom Line

If you’re looking for a conversion kit that will turn your pistol into a tactical beast, the CAA Micro Conversion Kit might be exactly what you’re looking for. Just add this onto your P320 pistol and you’ll have one that is battle-ready whenever you need it the most.

Pros

Fits Most P320 Calibers

Super Durable and Tough All Over

Easy To Assemble and Disassemble

Ambidextrous, Best For Left-Handed Shooters

Great For Concealed Carry and Tactical Applications

Cons

Some Fitting Might Be Required

Some Sizes May Compromise Concealability

Installation Might Be a Bit of a Challenge For Some Users

Best for the Money

B&T USA – USW-320 Upgrade Chassis

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What Recent Buyers Report

Most recent buyers used this chassis as the framework for their P320 pistol conversion. A lot of them were satisfied with the design being solid and durable. Their firing group assemblies from their pistols fit this chassis perfectly, making it ready to go for installing the P320 conversion kit of their choice.

What Recent Buyers Report

A chassis is the cornerstone of any conversion process. Without it, you won’t be able to convert your P320 into a different size or caliber. You can call this the framework of how to get it done. Other than that, it’s solid in construction and will actually serve you better in the long run if you intend to turn your pistol into an accurate force to be reckoned with.

Who Will Use This Most

This chassis will be a much-needed accessory for a successful pistol conversion. So it will be used across many users like your concealed carry users, law enforcement, military, and other users. Whether you convert it into a full-size or a compact, this chassis will fit your P320 kit of choice.

What Could Be Improved and Why

This chassis may need something that can turn into a nice package deal. We’re thinking a set of magazines will do quite nicely. For example, you can include a set of magazines that will fit a full-sized 9mm P320. This way, you get a great chassis to work with but also a set of magazines that will perfectly fit your newly converted pistol.

Bottom Line

If you need something to start your conversion process with, a chassis like the B&T USA USW-320 Upgrade will help get you started. This is the closest that you can find that will fit all kinds of P320 conversion kits (including those that are on this list).

Pros

Perfect For Concealability

Compatible With Most P320 Conversion Kits

The Grip is Nice and Solid, It Provides an Excellent Hold

Super Durable, It Can Handle All Kinds of Impact and Abuse

Very Accurate With Targets Situated From as Far as 50 Yards Out

Cons

None

Sig Sauer – Caliber X-change Kit Sig Sauer P320 Fullsize

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What Recent Buyers Report

A lot of recent buyers were able to easily convert their P320 pistols from sub-compact or compact to a full-sized pistol with ease. One user said he wanted to change things up. After the conversion, he was able to use his newly converted pistol as his most reliable concealed carry pistol yet. Previously, he had only used it for competitive purposes.

What Recent Buyers Report

This has all the vital components you need with the inclusion of one of the much-needed accessories that can make a P320 function: a magazine. The magazine will perfectly fit the mag well and will give you 15 rounds of extraordinary firepower. It’s an added convenience that even we can’t say no to. 

Who Will Use This Most

This will be a conversion kit that will be best used by those who want to convert sub-compact or compact sized pistols into a full-size. It will be great for concealed carry or even tactical situations for law enforcement or military personnel. Also, if you want a larger P320 this is the kit to go with.

What Could Be Improved and Why

With no obvious cons, we can still think of something that might be worth adding into the mix. Since a magazine is included, why not include a holster that will fit your new full-sized pistol like a glove. It can be an inside the waistband holster or an OWB holster. Either way, it will be the perfect addition to this kit and can be useful once you’ve successfully converted your P320.

Bottom Line

If you’re looking for a conversion kit that is considered the best of the best and would be ideal for turning your current compact or sub-compact pistol into a full-sized P320, this Sig Sauer Caliber X-Change Kit will definitely be right up your alley. Especially when you want an alternative to buying a new pistol that might set you back by hundreds of dollars.

Pros

Super Durable Components

Will Convert Into a Full-Sized P320

The Grip Module Works For Most Hand Sizes

The Magazine is Reliable and Allows For Smooth Shooting

Components Are Easy to Assemble Onto Your Fire Control Block

Cons

None

Sig Sauer – Caliber X-change Kit Sig Sauer P320 Carry

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What Recent Buyers Report

A lot of users were happy with the P320 conversion kit. They were able to try out new calibers that were different. One user converted his 9mm into a .45 ACP and said it was slightly better. He said that while he loves 9mm calibers, for some reason he’s decided to stick with the .45 on his P320 pistol.

What Recent Buyers Report

This may not be a size conversion of sorts for a P320. It’s more of a conversion kit to try out new calibers. There might be a time when you get tired of firing off the same old shots. That’s where this kit will come into play. You can switch out one caliber with the other and give it a spin. If you like it, keep it. If you don’t, switch it to something else.

Who Will Use This Most

This will be used by mostly concealed carry users who might be interested in a change in caliber. Some might not be satisfied with 9mm calibers and want to switch it to something with more power. And there might be those who want to convert from a .45 to a 9mm. Either way, there’s a caliber that you can consider your new “go-to” that will be ready for conversion.

What Could Be Improved and Why

This kit should include additional magazines that will perfectly fit the caliber that you choose. Some magazines can accept a 9mm, but won’t fit any other caliber rounds. It would lessen the frustration if you included magazines that would fit the appropriate shots you intend to use.

Bottom Line

If you’re looking to switch calibers on your P320, you’ll need a conversion kit that will definitely stand out. The Caliber X-Change Conversion Kit might be just what you need so you can upgrade your P320 pistol to the next level, even if it means switching out calibers.

Pros

Super Durable Components

Easy to Assemble and Disassemble

Magazine Fits the Mag Well Perfectly

Great For Converting From One Caliber to Another

Excellent Kit For You to Experiment With Other Calibers

Cons

Some Fitting May Be Required

Some Have Had An Issue With the Installation Process

Some Say the Magazine May Not Accept Some Caliber Rounds

Components of a Conversion Kit

There are a few key components that consist of an entire conversion kit. You’ll need to know what’s included so you know what you’ll get. Here’s what you’ll likely see in a P320 Conversion Kit:

Grip Module

A grip module will most definitely be a component you’ll need. However, you’ll need to know a couple of things about it before it’s either a “go” or “no go”. First, does it fit your hand size? Second, what type of pistol size is it (full-size, compact, sub-compact, etc.)? Don’t find one that will be ill-fit for your ideal P320 pistol.

Slide

Your slide will consist of the other half of the pistol itself. Once again, you’ll need to know which pistol you plan on converting it to so you can get the right size. Remember, a full-size slide won’t be able to fit a pistol that is considered compact or smaller. 

Slide

The slide is attached to the top part of your pistol. This will provide a sliding action each time you pull the trigger and fire your pistol. When the pistol slides back, it will discard the casing of the shot that you just fired. 

Sig Sauer – Caliber X-change Kit Sig Sauer P320 Fullsize

How to Choose a SIG P320 Conversion Kit

Finding the right SIG P320 conversion kit will take some time and a little bit of detective work. You need to know how to distinguish one from the other based on characteristics, what’s included in the kit, and any additional features that are relevant to you. Here’s what you need to look for while choosing a conversion kit:

Price

If you’re someone who tends to be a budget shopper, obviously the price tag is the first thing you’re going to look for. One thing to know is that it should not be the only reason why you should get a conversion kit. Don’t settle for something that’s low in quality just because it’s cheap. Always place quality at a high priority, even if it means buying a conversion kit that might be on the higher end of your budget scale.

What’s Included in the Kit?

All kits should include the right kind of components. Especially the ones you need the most. Some kits may have what you need to make a complete conversion while others might have some parts that may not be needed until sometime later on. Either way, be sure to choose a kit that will have your grip module and a slide to ensure that they are the perfect fit for conversion.

Materials

The components in each kit are made from high-quality materials. This will equal out to better quality and a better chance at lasting a long time. For example, the grip modules will be made from polymer because of its durability and ability to resist damage and abuse.

Benefits of Investing in a Great Kit

When you invest in a P320 conversion kit, you’re getting a few great benefits that will work to your advantage. It would be as if you’ve done an upgrade without buying so many accessories or tools. Here are some of the benefits you’ll get to enjoy with a new P320 conversion kit:

Better Concealability

Depending on which size your switching to, your pistol will be more concealable than ever before. This would be a great benefit to enjoy if you’re someone who conceal carries a pistol on a daily basis just in case danger might happen to lurk nearby.

Better Accuracy

Sometimes, converting your pistol may also be beneficial to your accuracy. It might depend on the size or even the caliber of the pistol you decide to convert to. Your shooting groups may tighten up if you’re shooting targets at various distances.

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Easier to Disassemble and Reassemble for Maintenance

Most factory default pistols will be a challenge to disassemble and put back together after a simple cleaning or routine maintenance. The components of a P320 conversion kit when put together are easy to assemble and disassemble, making the cleaning or maintenance a lot easier to do. 

Types of Conversion Kits

There are different conversion kits that you will want to choose from. It all depends on your personal preferences and needs when it comes to putting together the perfect P320 pistol. Here’s what’s available on the market today:

Full-Size Conversion Kits

This will have the parts you need to ensure that your pistol is a full-sized P320. This is the largest of the three available. It is also the standard size of a SIG P320. This will provide you with a good amount of concealability even if you’re converting it from a compact or sub-compact. 

Compact Conversion Kit

This is one size down from the full-size. However, it maintains the same characteristics of the full-sized pistol and its functions. This will be a lot better for those who want better concealability but don’t want the pistol to be too small for their hand size.

Sub-Compact Conversion Kit

The sub-compact is the smallest of the SIG P320 sizes. This provides shooters with the ultimate concealability. This will have the same characteristics and firing ability as their compact and full-sized counterparts, but it will be mostly used by those who have smaller hands. 

Conclusion

The best SIG P320 conversion kit is out there. You can choose to convert your full-size pistol to a smaller size or make an upgrade to size down for better concealability. If you want, you can even switch calibers. Either way, there’s a conversion kit just for your P320 pistol. Find the one that best fits your personal needs and preferences and you’ll be able to easily make the changes you want to it.

Josh Lewis the managing editor at Gun Mann and when he isn't writing about guns he is more than likely tinkering with them. He also enjoys hunting, fishing and spending time outdoors. As a lifelong gun owner he knows his stuff!

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