Is .40 S&W as powerful as .357 Magnum?

[Dave Lively]

Buffalo Bore has a hot rod 10mm that'll equal or exceed anything in .357 mag.

Except for Buffalo Bore's 357 ammo.

Yes, BB and Underwood do have heavily loaded 10mm ammo. But this thread is about the 40 S&W, not 10mm. Most people will agree that the 10mm is at least a little bit more powerful than a 357. But BB makes extremely heavy loads for the 357 too. It is unfair to cherry pick the hottest 10mm or 40 loads available and compare them to conservatively loaded 357 ammo.

Look at 180 grain bullet loads BB makes in all three calibers:

Heavy .40 Smith & Wesson +P Pistol & Handgun Ammunition
40 S&W +P = 1119 fps = 484 ft-lbs (5 inch barrel)

Heavy 10mm Pistol & Handgun Ammunition
10mm = 1351 fps = 728 ft-lbs (5 inch barrel)

HEAVY 357 MAG OUTDOORSMAN Pistol & Handgun Ammunition
357 = 1400 fps = 783 fps (5 inch barrel)

The 40 load above is labeled "+P" in a caliber where that can mean anything since there is no +P spec for that caliber.

When comparing calibers you shouldn't look at ammo from companies that explore the limits of how hot ammo can be loaded before guns become unreliable or break. If you want a semi-auto as powerful as the 357 magnum buy a 10mm, don't try to hot load a 40. Out of carry size guns the 40 S&W with light bullets is in the same ballpark as the 357 but comes up a little short.

 

[joeintexas]

I shoot a Sig P250 in 40 S&W and 357 Sig, I have also owned a 686 in 357 mag. I feel pretty confident in all of them. All of them shoot to point of aim at 25 yards. Not sure what some folks are trying to shoot that they think a 40 won't knock down at 1300 fps. By the way, I also own several 9s but I carry the larger bores, that's just me.

 

[gen3guy]

Wasn't the 125gr. .357Sig..... a bottlenecked .40 case ..... designed to replicate the 125gr .357magnum round fired from a 4" barrel.

It was designed to make you think it was, but it still falls a little bit short.

 

[johngalt]

According to the reloading manuals, no. At the same bullet weight, the .40 is also slower than the .45 auto.

 

[snowman.45]

I don't currently have a .40 or a 10mm, but I've owned a number of .40 Glocks and S&W M&Ps in the past, as well as a 1066. I really like the 10mm round in a semi-auto. As a retired LEO, I pretty much carry .38/.357 J-frames, .45 1911s or sub-compact and compact 9mm semi-autos on a daily basis. I don't feel under-gunned with any of them, but then, I believe in shot placement as being the deciding factor over ballistics.

As a firearms instructor for about 28 of my 37 years, I've trained officers in .38/.357, 9mm and .45 ACP. I never worked for an agency that issued the .40 S&W, but have worked beside a number who do/have. I have been asked by range staff from some of these agencies what duty round we carried in the 9mm, because of our incapacitation rate in officer involved shootings. Folks were impressed with the effectiveness of the Speer Gold Dot 124 +P round we issued, and when compared against .40 and .45 rounds in center mass hits, the damage and penetrations was equal to superior in most situations. This was so much so that I often got the question about ammo by those who intended to report back to their administrations.

Don't get me wrong; I prefer .45 ACP to most anything for daily carry, although 9mm and .38/.357 don't make be feel inadequate. In the mountains or desert, I'm usually carrying .357 mag. Around town, capacity concerns will sometimes lead me to carry the small 9mm guns. But to address the original question, I'm certain .40 S&W will perform with the appropriate level of lethality with proper shot placement; but ballistically, I don't think it's quite to the level of .357 mag. And, to respond to other comments regarding 9mm, most calibers have enjoyed higher performance levels with improved bullet and propellant technology, but this technology has raised 9mm to a level that makes it significantly more effective than it was back in the early days when law enforcement agencies first began to issue it. Hell, as a young cop in the 70's we would never consider a 9mm over .357 mag. or .45 ACP. Things are a little different today.

 

[jack the toad]

Not trying to hijack, drift or throw a wrench in the works but while checking ballistic tables for similarities between .44 Special and .45ACP, I noticed similarities between heavier .40S&W (180 & 200 gr. range) and similar .44 Special loads. Not surprising but just never thought about it.

 

[hkcavalier]

You mean diminishing returns? It sounds like your Coonan is the poster gun for diminishing returns.

Just exactly how fast does a handgun bullet have to travel to reach maximum efficacy?

Not sure what you mean...how is a 125 grain pistol bullet at 1800 feet per second and within pressure guidelines "diminished"?

Diminishing returns would be a noticeable increase in noise, flash, and recoil for just a meager gain in velocity. Like a .357 J frame snub over a .38 Special +P.

 

[mdf9183]

For all those folks that want use and shoot what the Military and LEO use in weapons and ammo, you have to realize they really don't have a choice in what they use. That is done by some bureaucrat sitting in an office somewhere. It may not exactly be the best gun or ammo available but it is probably the least expensive to the bureaucrat.

 

[Buckeye63]

Im a big 357 Mag fan .... and the 357mag 125gr JHP is known as a manstopper ...
But having said that my EDC is a Glock 27 loaded with 180gr HST ... for SD carry this combo is hard to beat ...

The 357 Sig with Underwood 125gr Gold dots are equal to the 357mag 125gr

The 10mm when loaded to its full potential , like Underwood ammo offerings .. Is between the 357mag and 41mag ..

 

[Faulkner]

For all those folks that want use and shoot what the Military and LEO use in weapons and ammo, you have to realize they really don't have a choice in what they use. That is done by some bureaucrat sitting in an office somewhere. It may not exactly be the best gun or ammo available but it is probably the least expensive to the bureaucrat.

That's not been my experience. In all of the departments that I interact with (which is quite a few) the training officers and supervisor staff have quite a bit of input in model of firearm, caliber, and ammo issued. Sure, cost is an issue but it's only part of the equation.