Who wants to shoot just one caliber?
Modularity is a defining factor of many modern firearms, and a big chunk of modularity is the ability to swap calibers.
As we’ve seen in relatively peaceful times, your favorite ammo can dry up in a hurry. Swapping calibers can be vital for putting food on the table, training, and even self-defense.
The prepper side of my brain says more options are always better than less, and being able to swap calibers is undoubtedly a handy thing to have when the zombies come knocking.
While It’s true that with enough tools, expertise, and machinery, you can turn dang near any gun into something multi-caliber, that’s not what we are talking about today.
We are talking about common weapons where the end-user can easily swap calibers without custom work.
So with that in mind, I’ve gathered what I think are the best multi-caliber weapons currently on the market that are easy for the end-user to swap calibers, starting with the weapons that have the least amount of caliber swaps to the most.
Summary of Our Top Picks
Best Multi-Caliber Weapons
1. Sig Sauer P320
Sig designed the P320 to be a modular platform. That was always the intention, and that idea dates back to the original and somewhat underrated P250.
They wanted to maximize the use of their FCU — Fire Control Unit.
The FCU is the serialized portion of the gun, thus making it legally the firearm. This allows the FCU to be moved into different frames and work with various slide and barrel lengths.
In addition to being able to move from full size to subcompact, the P320 can also swap calibers.
If you own a P320 in .40 S&W, you can purchase what’s known as a Caliber X-Change kit to swap your caliber from .40 S&W to .357 SIG or 9mm fairly easily.
Some kits require more than others, but typically you get a new slide, barrel, frame, and magazine.
Swapping between frames and calibers is easy and can be done in about two minutes without needing tools. Sig had a great idea, but it’s at the top of the list because they’ve seemed to abandon it.
Sadly, Sig never moved past these calibers and seems stuck here. Moving from 9/40/.357 SIG to .45 ACP or 10mm is an option.
The Caliber X-Change kits are also fairly expensive, and for a few dollars more, you could purchase a second firearm rather than swap calibers.
2. Taurus 692
The Taurus 692 is all kinds of cool. It’s a 7-shot revolver that allows you to swap cylinders.
One cylinder will enable you to fire .38 Special and .357 Magnum, and the other allows you to fire 9mm.
Having one revolver fire three calibers makes it an excellent choice for various applications.
The 692 comes in various sizes, from models designed for concealed carry all the way up to weapons perfect for hunting. Taurus added porting to the barrel to increase control and reduce recoil, as well as an adjustable rear sight.
Sprinkle in an extra shot for a seven-round capacity, and you get a very capable revolver.
With .38 Special, you get a very soft shooting caliber.
If you want to shoot cheap ammunition but also have a good selection of various defensive loadings, 9mm has you covered. In the .357 Magnum department, we get a flat shooting caliber that is capable of defense and excellent for hunting small to medium game.
I think the 3-inch barreled model is the most versatile, but shooters can also pick from 2.5 to 6.5-inch options.
With the 692, you get a versatile revolver that’s also affordable. Being able to switch between 3 calibers isn’t bad for a budget-friendly handgun.
3. “Most” 1911s
With such an illustrious history and long lifespan, the 1911 has been offered in many different calibers. It is also a gun that’s easy to convert to a different caliber.
Of course, with millions of 1911s produced, some are bound to work better than others with various calibers.
Thus the “most” caveat in the title. How easy it is to swap between calibers depends on what caliber your 1911 was originally chambered in.
Moving from a .45 ACP to another caliber takes the most effort and essentially requires an entirely new slide and magazine.
Going from 9mm to .38 Super or 10mm to 40 S&W is much simpler, being as easy as a barrel, recoil spring, and magazine swap.
Prices accurate at time of writing
Prices accurate at time of writing
Swapping from 9mm to 10mm will take a new slide, and so will changing from any caliber to .22 LR.
Luckily with the wide availability of 1911 parts and the extremely common frame, you can make it happen fairly quickly.
You can even swap in various oddball calibers, like .22 TCM or .50 GI. Sure it requires some creativity and a little know-how, but it’s not too intensive or difficult to mix things up with your 1911.
4. FK BRNO
When someone says a new gun is revolutionary, I typically roll my eyes.
Sure, I’m betting whatever new striker-fired polymer 9mm is revolutionary. However, with the FK BRNO PSD, they were right, and it’s awesome.
Its unique 7.5 FK round hits some spicy velocities and is flatter shooting than just about any other pistol cartridge.
The BRNO has an interesting and unique design, but its ability to swap calibers has put it on this list.
You can swap between 7.5 BRNO to 10mm, .40 S&W, and 9mm with the purchase of the necessary parts.
It might not be cheap, but it’s a damn fine pistol. To be fair, plenty of 2011s cost more than the BRNO and don’t offer near the flexibility of this gun. Imagine using 7.5 BRNO to kill a deer 50 yards away, then swapping to 9mm for self-defense use.
Whether you are target shooting, hunting, or stuck in the zombie apocalypse, that versatility can be handy.
5. Glock 20 & 29
As crazy as it is to say, Glocks are a lot like 1911s in a sense. Their popularity ensures a robust aftermarket that includes caliber conversions.
Calibers you can easily move to include .40 S&W, .357 SIG, 9x25mm Dillon, and .50 GI. Rimfire replacement slides also exist. These are the standard conversions that work with no issue.
There is also something to be said for the 10mm and its wide variety of loadings.
You can get several different projectile designs with varying power levels for everything from defense against humans and to loads powerful enough to take down a bear.
These Glocks are arguably the most versatile of the Glock pattern pistols.
The Glock 29 offers you a subcompact hand cannon, and the Glock 20 delivers full-size potential. You can get a little bit of everything with either of these guns.
6. Savage Arms/Stevens 301 Turkey
The Savage/Stevens 301 Turkey is a single-barreled shotgun available in the most popular shotgun calibers.
For the best multicaliber option, you’ll need the 12-gauge model. I chose the Turkey variant specifically because it’s one of the rare single-shot shotguns that’s optics ready.
How exactly is a single-shot turkey gun multi-caliber? Well, it’s not all by itself. You’ll need some Short Lane adapters.
These inserts allow you to convert your shotgun to various calibers, including other shotgun calibers like .410 and 20 gauge. On top of that, the Bug Out and Pathfinder series offer five and 8-inch rifled inserts, respectively.
These caliber sleeves allow you to shoot .22 LR, 9mm, .38 Special, .45 ACP, .45 Colt, and more in your shotgun. This takes any already flexible platform and makes it even more versatile.
The Savage 301 Turkey is a robust and reliable shotgun, so it was an easy pick. Top off the rail with something like the Meprolight Foresight, and you can have multiple zeroes for each caliber conversion.
While I’d love to see a .300 Blackout option for the 8-inch inserts, the current options for inserts are plenty diverse. You can do just about anything with the right adapter and a single-shot shotgun.
Of course, the AR-15 had to make the list. Like the 1911 and Glock, the AR-15 is immensely popular and inherently modular.
Users can convert it to various calibers in multiple ways, including changing the barrel, dropping in a conversion kit, or swapping uppers.
Even removing and changing the barrel isn’t that difficult, but the easiest means is to just switch the upper. There is a reason most AR lower receivers say multi-cal.
You can change a standard 5.56 to .300 Blackout, .224 Valkyrie, 6.5 Grendel, 6.8 SPC, .458 SOCOM, .50 Beowulf, and so many more by simply changing out the upper and maybe the buffer.
A 5.56 rifle can also be converted to numerous pistol calibers with an upper and buffer swap. The user then needs to find something like the Endo Mag or an insert from Matador Arms to convert the magazine well to use handgun magazines.
If you want a rimfire rifle, you can swap uppers, but the CMMG bolt system is an easier method.
This drop-in bolt and magazine system allows you to shoot .22 LR from your standard AR-15. Your zero may shift a bit, but it’s surprisingly reliable and easy to use.
Heck, I even own a .410 upper for one of my ARs.
Have you ever heard of .277 Wolverine or 25-45 Sharps? Well, you can get an AR in those. The number of calibers the AR can accept is stunning — it’s only beaten by one gun.
7. Thompson Center Encore Series
The Thompson Center Encore Series of rifles and pistols are single-shot firearms designed for quick and easy caliber conversions.
Shooters can easily remove the barrel, replace it with another, and instantly convert it to a new caliber.
What caliber do you want?
Want to convert your .308 to a 12-gauge? Well, you can. Want to shoot .500 S&W one day and .243 the next? Swap barrels and do it.
If there is a caliber, chances are there is an Encore barrel for it.
The Thompson Center Encore series is compatible with all Encore and Pro Hunter barrels. Shooters can even change the very nature of their guns by turning a rifle into a shotgun or a muzzleloader.
Aftermarket companies even produce more barrels, and companies like match Grade Machine produce some oddball calibers you won’t see anywhere else. Barrel swaps are easy, and the sights are attached to the barrels, so zero is held when detached.
The real downside is the price of the barrels. They aren’t cheap by any means, but there are a mind-boggling amount of calibers available. With that in mind, the Encore series takes the top spot.
A gun that can shoot just one caliber can be boring. Being able to quickly and efficiently shoot a variety of calibers can be a huge benefit and is a great selling point to some.
There are other great multi-caliber capable guns out there, these are just a few that I like.
What’s your favorite multi-caliber weapon? Do you have any experience with any of the guns on the list? Let us know in the comments below. Not sure what calibers to look for? Check out our guides on Handgun Calibers and Rifle Calibers.