357 Magnum vs 9mm – The Ultimate Showdown

by Travis Pike

January 6, 2022



Oh boy, today we have a hot one. We are comparing two of the most efficient handgun cartridges of all time. The 9mm and the 357 Magnum. Handgun calibers range far and wide, and these two calibers are two examples of how versatile handguns can be. This debate transcends caliber and really reaches at the heart of the revolver vs. semi-auto debate. As such, it’s going to be a fun one because these cartridges are so much different, yet oh so similar. 

357 Magnum vs 9mm Specs

Specifications9 x 19mm357 Magnum
Bullet Weight115gr to 147gr125gr to 180gr
Bullet Diameter.355 inches.357  inches
Case Length19.15mm33mm
Max Overall Length29.69mm40mm
Case Capacity13.3gr H2026.2gr H20
Max Pressure34,084 PSI35,000 PSI

Why Compare the 357 Magnum vs 9mm?

Both are extremely popular, capable, and proven. In many ways, they are the best combat cartridges in their respective platforms and in their respective genres. What makes this a fun comparison article is that these two calibers are very much the same but also much different. It’s kind of a weird walking contradiction. 

The projectile sizes are almost entirely identical. The 9mm uses a .355 caliber bullet and predictably, the 357 Magnum utilizes a .357 caliber projectile. That .002 could be a rounding error anywhere else. Both rounds came to be for martial use, with the 9mm intended for military forces and the .357 Magnum for police forces. 

Both rounds served faithfully in law enforcement roles, in concealed carry roles and far beyond. While they have a lot in common, they are also completely different. The .357 Magnum is primarily a revolver cartridge intended to provide new levels of power to the fighting handgun. The 9mm is primarily an automatic cartridge that strikes a balance between power and capacity. 

Since both rounds have seen such popularity with law enforcement, concealed carry, and home defense, it makes sense for us to give them an in-depth examination. Those of you coming to Gun University to find the right home defense gun for you, are wise to research the various calibers as well various gun models. 

9mm Review

Let us start with the 9mm cartridge and dive into its history, purpose before pitting the two cartridges against each other.

History and Purpose

9mm Ammo

The 9mm has been around for way longer than most people know. It might be the round of choice for modern military and police forces, but the 9mm goes all the way back to 1901. In 1901 Georg Luger decided he didn’t need an E at the end of his name, and the world needed a new bullet. That bullet would use a 19mm case and a 9mm projectile. 

The round originates from the 7.65×21 Parabellum, but the shorter profile allowed it to function better with the Luger pistols toggle lock and allowed for a more ergonomic grip. Long rounds make wide grips, and wide grips aren’t overly comfortable. At the same time, the round packed a sufficient-sized projectile for the case capacity to deliver efficient energy on a target. 

The 9mm round would go to serve in World War 1, World War 2, and every war since then. The cartridge became massively popular in pistols and submachine guns. Europe was the first to adopt the 9mm and did so with great gusto. In World War 2, both the Axis and Allies utilized the 9mm. Specifically, the Brits Sten gun faced off against the Nazi MP40 in combat, both blasting 9mm from submachine guns. 

Eventually, the United States got over their 45 ACP lust, and the 9mm became the dominant cartridge starting in the 1980s. 

Since then, it has become the round of choice for NATO, the United States military, and most modern police forces. These days it’s the dominant round in the United States and continues to be the round of choice for a wide variety of shooters. Since the round has been around for over a century, it’s benefited from research and design and lessons learned. 

This included effective projectile design involving jacketed hollow point rounds. These JHPs helped narrow the gap between the 9mm and larger rounds like the 40 S&W and 45 ACP.

9mm Ammo Recommendations

Where do you start with a cartridge that’s been around for over a century. Here’s our recommendations of 9mm ammo for different scenarios.

For the Range

Magtech 9mm Ammo
Cost Per Round
Natchez $0.24
Brownells $0.23
Palmetto State Armory $0.34

Working Ammunition

Barnes 9mm Ammo
Cost Per Round
Palmetto State Armory $0.92
Natchez $1.15
Cabela’s $1.39

357 Magnum Review

Continuing on, let us look at the 357 Magnum’s history and purpose and some ammo recommendations before we really jump into the comparison of these two rounds.

History and Purpose

Although World War 1 made the automatic pistol mainstream, most American police forces stuck with the proven six gun design. Revolvers ruled, and most revolvers utilized the 38 Special round. As the Roaring 20s gave way to the prohibition era, gangsters of the 1930s law enforcement needed something new. 

357 Magnum Ammo

The 38 Super Automatic was one of the only rounds that could penetrate the metal of car doors with any kind of efficiency. Police wanted a revolver round that could do the same. Bootleggers and bank robbers were motorized, and that factored into developing a new revolver round. 

A group of experts began doing various experiments with suped-up 38 Specials on 44 frames. This lead to tougher, higher velocity rounds that could pierce the thin metal that car doors were made from. In particular, Elmer Keith worked hard to make a suped-up 38 Special a reality. Smith and Wesson made the 357 Magnum a reality and produced the first 357 Magnum revolver. 

The industry took notice and began producing a variety of 357 Magnum revolvers. Colt specifically happily adopted the round in their numerous “Snake” guns. The new round was slightly longer than the 38 Special to ensure shooters could not accidentally load 357 Magnum rounds and cause a handheld explosion. 

The new 357 Magnum cartridge became a reality, and the law enforcement world became big fans with state, federal, and local police forces adopting it rapidly. The heavy-hitting cartridge proved quite successful and became a well-known man stopper. While revolvers and the 357 Magnum have faded from duty use, it’s still a popular configuration and caliber among civilian shooters. 

357 Magnum Ammo Recommendations

Below are our recommendations for 357 Magnum ammo for the range and home defense.

Great for the Range

Sellier & Bellot Revolver .357 Magnum
Cost Per Round
Sportsman’s Guide $0.77
Lucky Gunner $0.83

Great Defensive Ammo

357 Mag - 110 Grain SJHP - Remington
Cost Per Round
GunMag Warehouse $1.14
LuckyGunner $1.03

The Many 9mm and Few 357’s

Before we go any deeper, we need to address that quite a few 9mm rounds exist, especially because of the pistol varieties. 9×19 is the round that dominates the 9mm field and is also known as 9mm NATO, 9mm Luger, 9mm Parabellum, 9×19, and just 9mm. Other 9mm rounds include the 9×21, 9mm Short (aka 380 ACP), 9mm Browning, (also 380 ACP) 9x23mmR, 9mm Makarov, and 9mm Glisenti. 

Needless to say, there are lots of 9mm ammunition, and the 9×19 goes by many, many names. It can be confusing but worth noting. The good news is that most places only carry the 9mm we all know and love. 

357 Magnum is the only 357 Magnum but isn’t the only 357. The 357 SIG is the other 357, and it’s a bit of a mix between 357 Magnum and 9mm. It’s a 9mm projectile loaded into a 40 S&W case. It flies fast and hits hard, but it’s not a 357 Magnum. 

The .357 Remington Maximum is a suped-up 357 Magnum that’s an absolute powerhouse of around. It’s insanely powerful and too long to fit into a 357 Magnum cylinder. A similar round to the Remington Maximum is the 357 SuperMag which is slightly longer than the Remington variation but roughly the same kind of power level. Oh, and apparently, in Europe, 357 Magnum is known as 9x33mmR, or so they say. 


Both rounds offer you outstanding performance for what they are. However, they are very, very different. The 9mm is a bit of an intermediate pistol round designed primarily for automatic pistols. A 9mm round weighing 124 grains reaches 1,150 feet per second and strikes with 364 foot-pounds of energy. Admittedly that’s average in terms of ballistics, and it’s no 10mm and certainly no 357 Magnum. 

The 9mm will routinely reach the FBI standards for penetration through 12 inches of ballistic gel. This means in a defensive scenario, the 9mm has no issues reaching the vitals of a bad guy and effectively stopping the threat. Historically many have looked at the round as anemic, they’ve often failed to understand that pistol rounds suck in general and the difference between most automatic cartridges is nil. 

The 357 Magnum is an entirely different beast. I mean, there is a reason the name Magnum stuck with this round. All that case capacity opens up the potential and possibilities. The 357 Magnum round loaded with a 125-grain projectile reaches almost 1,500 feet per second and strikes targets with 585 foot-pounds of energy. Needless to say, ballistically, it outperforms the 9mm. 

The 357 Magnum also has no problems reaching the FBI standards and even exceeding them. While the minimum is 12 inches, the maximum is 18 inches. Past 18 inches, and you risk overpenetration, and the potential to strike an innocent person or destroy property increases. Proper self-defense bullet selection is a must when shooting the 357 Magnum. 

357 Magnum vs 9mm

Both rounds are meant for handguns but have found their way into long guns. 9mm is the caliber of choice for semi-automatic carbines, and the 357 Magnum sits pretty in lever guns. Both rounds have their effective range extended from a long gun and do well in these platforms. 

The 357 Magnum predictably does much better. When loaded with a Hornady Flex tip or Leverlution round, the 357 Magnum has hardly any drop out to 100 yards from a 16-inch barrel. With regular 357 Magnum ammo, you see a few inches of drop at best. With 9mm, we are looking at 10 to 12 inches of drop out to 100 yards and the potential for lots of wind drift. 

Without a doubt, the 357 Magnum kicks 9mm butt when it comes to effective range, energy on target, and wind drift. While both rounds work well for self-defense, the 357 Magnum kicks ass in the realm of hunting. 

Recoil and Muzzle Rise

357 Magnum kicks butt ballistically, but as you’d imagine, you pay for it via recoil and muzzle rise. The 357 Magnum is not some kind of crazy powerful cannon that kicks your butt up and down the range. That being said, the gun certainly has some recoil and muzzle rise compared to the 9mm. 

In a duty-sized revolver with a big heavy frame and 4-inch barrel, the 357 Magnum is a tight little shooter that’s slightly stout. Not a big problem, but follow-up shots will always be faster with a full-sized 9mm automatic. It’s just the nature of the beast. 

We see a massive difference when we shrink the guns. If you choose a 357 Magnum in a snub nose design, the gun becomes much less manageable. An air-weight snub nose is a literal handful to hold onto when you start spitting lead. A smaller 9mm might be snappy, but it’s heavenly compared to a 357 Magnum snub nose. 

There is something to be said for a 357 Magnum’s ability to chamber a 38 Special round. These heavier frame guns can very safely fire the tamer and mild recoiling 38 Special and 38 Special +P loads. These make the gun much tamer and easier to shoot. 

It’s the nature of the beast, and there is no such thing as a free lunch. If you want that 357 Magnum power, you’ll pay for it. If you want high capacity and low recoil, you have to sacrifice power to get it. 

Weapon Choice

Both guns are incredibly popular with a massive catalog of firearms available for each caliber. You can pick pistols, revolvers, rifles, and beyond in each caliber. Check out our article on the Best 9mm Pistols and the Best 357 Revolvers to expand this topic more. 

This being said, there are certainly way more options in the 9mm world than in the 357 world. 9mm has not only been around longer but it’s been popular longer. This translates into more handguns by a large margin. The same goes for rifles since the PCC world has exploded recently. 

9mm in rifles and pistols has the benefit of heavy subsonic loads that are easily suppressed. Suppressing a revolver isn’t possible unless the gun uses some form of gas seal design like the Nagant revolver from World War 2. 357 Magnum aficionados can use suppressed lever guns to have a very quiet and capable suppressed rifle. However, their suppressor compatible handguns are nearly nil. 

Regardless of what gun you choose, you’ll have plenty of options for a variety of different firearms. 


Firearm prices vary widely between the two. However, if we compare like with like, you’ll quickly figure out the modern 9mm is cheaper than the modern 357 Magnum revolver. For example, an S&W M&P 9mm has an MSRP of 610 for the basic model, and a Smith and Wesson Model 19 has an MSRP of $883. 

This is a common theme between various companies. A revolver is often more complicated than a polymer frame automatic pistol, and therefore the cost is higher. You can find cheap 357 Magnum revolvers, often imported, and they can be quality firearms. At the same time, imported polymer frame pistols can be much, much cheaper. 

When it comes to ammunition, the same is true. 9mm has the benefits of economies of scale to push the price down. In normal times 9mm is ultra-cheap and perfectly affordable for training, competition, and the like. 357 Magnum ammo can often cost three to four times as much as 9mm. When it comes to defensive ammo, the gap shortens a bit, but not enough to really note. 

The only real cheap ammo for a 357 Magnum is 38 Special. These rounds are cheaper than 357 Magnum loads and work well for practicing with a gun. However, even 38 Special loads cost considerably more than 357 Magnums. 

Our Take – Revolver vs Automatic

The argument between 9mm and 357 Magnum is a reflection on the argument of revolver versus automatic. The 9mm exemplifies everything great with an automatic pistol. Like the mild recoil, the potential for 15 to 20 rounds in a magazine, and the suitable ballistic backed by fast follow-ups. 

The 357 magnum exemplifies the raw power a revolver can offer you. That long case packs tons of power behind the small projectile. It hits hard and delivers a lot of power per shot. The big Magnum-powered revolvers pack a punch and can allow you to have a very versatile round for a variety of tasks. 

Either way, both concepts are well proven. That being said, the 9mm seems to excel more for concealed carry pistols and for defensive firearms. The higher capacity and faster follow-up shots are invaluable for defensive shooting. 

While the 357 Magnum will be an effective tool for defense, it’s better elsewhere. This caliber offers you plenty of punch for a defensive protocol that might involve big animals and two-legged vermin. It’s also a very effective hunting round capable of taking medium game without much argument. 

All 9’s

It’s crazy how two 9mm or .355/.357 projectile-based cartridges have become the mainstays of their respective designs and platforms. Both served the world well and continue to do so as very prominent and capable calibers. Like most caliber decisions, the differences between the cartridges are reflective of different ideas.  

When choosing one or the other, you’ll have to reflect on which works best for your specific tasks. The 9mm does things the 357 Magnum can’t do and vice versa. The good news is, both calibers are efficient and capable, so it’s hard to go wrong. Heck, do what I’ve done and just buy both. 


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About Travis Pike

Travis is a former United States Marine Corps Infantryman and currently a firearms writer, instructor, and works in Emergency Management.

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