.40 to .357 sig

I started converting from the .40 S&W to the 357 sig, & Vice Versa, in 1999, with the Sig Sauer P-239, The P-229, the P-226, and the Sig Sauer P-229 Sport Pistols.

The 357 sig cartridge displays a flatter trajectory than the .40 S&W, with a smaller diameter bullet of .355, rather than .357. If you have every fired a 125 gr. bullet from a heavy frame .357 magnum revolver, you will know what to expect from the 357 sig. The bottle necked case of the 357 sig feeds very smooth and fast. The sound report of the 357 sig is much like that of a four inch Colt Python, shooting 125 gr. factory loaded FMJ magnums. The muzzle flip isn't much more noticeable than that of a 38 Super in a similar pistol. I do shoot the 38 Super in the Sig Sauer P-220, and it feels much the same as the 357 sig in my P-226.

Most people who has bought into the conversions do not regret it, Myself being one.

 

Oh Yeah, SamHain; I do buy the georgia arms ammo for the 357 sig; I have used many others but georgia arms is far more affordable to shoot.

 

Coming back at you with another thought. The Georgia Arms loaded 357 sig, in their Gold Dot Bullet and Starline Case is one of the best, at 1400 fps.

Shop around; On the Sigs, I've often found factory barrels for $100. Most of my Pistols use the same magazines for the .40 and 357 sig, with the exception of the single stacking P-239.

 

Not all .357 sig ammo is created the same. Speer makes two different 125 gr HP's. One has a shallow hollow point similar to the .357 mag GD's. The other is a deeper HP that looks more like a conventional 9mm bullet. The shallow version was the original one developed for the Texas DPS. They want a load that will penetrate cars. It does so very well. It does not expand well in flesh. It acts more like a FMJ. The deeper bullet expands very well in flesh but does not do as well through cars. If you do not plan on shooting through cars get the deeper HP.

The Sig round is compared to the .357 mag but there is no real comparison. The .357 mag is far superior to the Sig in gun fights, IMHO. I think the reason revolver rounds stop people better is the bullet profile. Feeding is not an issue with the revolver. The mags tend to have more blunt noses that expand more reliably than autos. Auto pistol rounds have to feed into the chamber reliably and that makes for a more rounded profile that does not react as well in flesh.

This is, of course, my opinion. An opinion based on 30+ years studying ballistics and 24 years in LE. Your mileage may vary.

 

WOW; I didn't know the 357 sig has been around that long; Just shows what I know.

 

Robocop; The 357 sig IS a 9mm bullet. You kept referring to it as .357 sig, where I referred to it as 357 sig; It is actually a .355 caliber bullet. I think I mentioned this in my initial response.Notice now why I did not place a decimal point in front of the 357 sig. The 125 gr. 357 sig and the 125 gr. .357 magnum share the same velocities in most standard factory loads. I'm not trying to bust your chops on this; so don't fly over the top about it. I've been on the 357 sig for a while now, almost since it's introduction.

 

Very true the 357 sig is a .355 (9mm). On paper the Sig and the Mag look the same. The reality is different though. .002 diameter difference (actually .003 as the .357 mag uses .358 bullets) is not the issue. I believe it is bullet profile. A rounded nose S/A pistol bullet does not act the same as the more blunt profile of the revolver bullet. Texas DPS bought into the hype of the Sig round very early. I have heard their people rever to it as a semi-auto .357 magnum. It is not. It was not coincidence that Sig named it 357. It was marketing. You could have called it a 9mm magnum and hve been closer to the truth. He!!, the term magnum is marketing hype. If you like the Sig, go for it! Most foldks would be better off with a 9mm and a couple of cases of ammo. Practice, practice, practice. chew out the center of a target. Attend a good class or three that teaches sound tactics. One good hit is far better than spray and pray.

 

I could have, but I think the 38 super had already laid claim to that one some years ago. The 357 sig was not the first to market a cartridge's bullet diameter by that of another name, as we know with the 38 special, 38 super, 44 magnum, and others.

I've fired the .357 magnum in the S&W N frame, L-frame. J-frame, and Colts Python. I fired the 357 sig in four frame platforms of the Sig Sauer pistols. These are sidearms of my own personal choice for these cartridges.

One significance I've found with the 357 sig is the ability of a smaller, light weight, personal size, semi-auto having to consistently stand up to the diet of such a cartridge, while still exhibiting a level of comfort for the shooter.

In my own humble opinion of shooting and being around handguns for over 40 years; The 357 sig /.40 S&W combo was the best thing to come around since the revolver compatibilities with the .357 magnum/ 38 special and the 44 magnum / 44 special. Although it involves changing barrels in the semi-autos; Thanks to the close and consistent tolerances of CNC manufacturing, we have barrels which drop in as if they were part of the original pistol from the factory. With a pistol like the Sig Sauer; Changing barrels is one of the most attractive ergo features in it's design.

I noticed you quit placing the decimal point in front of the 357 sig; Thanks.

I enjoy reading your posts and I hope you feel the same of mine.

 

.40 S&W vs. .357 SIG

I have had the pleasure of communicating with Massad Ayoob on another forum and I asked him if I could quote his review on these two cartridges. He said that would be fine. This is out of The Complete Book of Hanguns 2008.

.357SIG
In the early 90's, spurred by Texas troopers and rangers who loved the SIG SAUER .45ACP pistol, but missed that "lighting bolt" stopping power effect of their old .357 Mag revolvers, SIG SAUER worked with Federal Cartridge to create the .357 SIG round, It resembles a .40 necked down to 9mm, though the actual construction is somewhat more complicated than that. Different companies load to different velocities, and depending on the pistol and barrel, factory 125-grain JHP's are delivering 1325 to over 1400 fps.
High-tech bullets that open rapidly, but stay together seem to work best in this caliber. The most widely proven is the Gold Dot. From Texas to Virginia, it has been kicking butt with no horror stories of stopping failures. New Mexico State Troopers fell in love with the .357 SIG a few years ago, and stayed with that cartridge when they ordered their new S&W M&P autopistols. North Carolina Highway Patrol gave up it's beloved Beretta pistols after more than 20 years to adopt the SIG SAUER, because they could get it chambered for .357 SIG.
Gunfights indicate that this cartridge is particularly good for shooting through auto sheet metal and window glass, yet does not deliver on the street the dangerous over-penetration that some gelatin tests had indicated might happen. The spent, expanded bullets are normally recovered from the far side of the criminal's body, or from his clothing, or from the ground within a few feet behind where he was located when shot.
Winchester Ranger in 125-grain .357 SIG had worked well in actual shootings. Remington Bonded Golden Saber in 125-grain .357 SIG is deliciously accurate, and perfoms superbly in FBI protocol gelatin testing, though I haven't run across any actual shootings with it yet. The overwhelming majority of .357 SIG shooting by police have occured with 125-grain Speer Gold dot, and it has worked so well it is unquestionably the most "street proven" load in this caliber.

.40

Introduced in 1990 by S&W and Winchester, this 9mm length, 10mm cartridge was designed to split the difference between the 9mm's higher round count in the gun and the .45ACP auto's larger caliber. It succeeded hugely at that in police work, being chosen by more law enforcement agencies today than any other. It has become popular among armed citizens for that exact same compromise factor.
First generation ammo, a 180-grain subsonic with a conventional JHP bullet, did better than expected, but still wasn't spectacular. It pretty much duplicates the ballistics of the old .38-40 black power handgun load of the 19th century frontier. I've run across a lot of shoot-throughs with 180-grain standard JHP, more than would be desirable for home defense.
Those who like the 180-grain subsonic's ballistics want to go with high-tech hollowpoints that open more aggressively, penetrate a little less, and seem to produce a more decisive stopping power. The 180-grain Gold Dot has earned a good reputation in cities such as Boston and Milwaukee. The 180-grain Federal HST has produced some truly impressive one shot stops in the Pacific Northwest. The 180-grain Winchester Ranger, particularly in its latest iteration, also works distinctly better than a conventional copper-jacketed bullet of this weight and velocity.
It appears that the medium-weight bullets at higher velocities are providing the best combination of penetration depth, expansion, and overall decisiveness of ending encounters. Not the 165-grain subsonic .40, the so-called "minus-P," but the 165-grain JHPs traveling at 1140 fps and 155-grainers at about 1200 fps. the latterhas worked very well for the US Border Patrol, which seems to have used mostly the Remington brand. Other non-high-tech .40 caliber JHPs in this weight range that have delivered impressive performance are Federal Classic and the Winchester Silvertip, both 155-grainers. These are also less expensive than the top-line premium lines.
High-tech bullets still do well in this weight range, though. The 165-grain Winchester Ranger and Speer Gold Dot seem to lead the pack by a narrow range.

I would like to thank Mr. Ayoob again for letting me quote his article on these rounds. Mark

 

Thanks For The Massad Quote; I've read many of his articles and enjoy his feed back.

During my first response on this thread, I recommended the Georgia Arms Ammunition company, which loads the Gold Dot Bullets on Starline cases. I use their ammunition in most all my revolvers and semi-autos, with the exception of a few others.

Although the 357 sig case resembles that of a necked down .40 case; The 357 sig case is actually constructed with thicker case walls than the .40 S&W.

If I'm carrying a .40, rather than a .45 acp or .357 magnum, I usually load it with the 135 gr. Corbon, which is rated at 1300 fps. And this is in a smaller lightweight personal size semi-auto in that of the Sig Sauer P-239.

I'm not saying the 357 sig is in anyway designed to clone a carbon copy of the .357 magnum in the semi-autos. What I am saying is, it places the smaller lightweight pistols in a far different perspective, for those looking for this kind of velocity from a mid size bore diameter semi-auto. Mimicking the 125 grain .357 magnum, in a semi-auto, is what the 357 sig attempts to accomplish. If one were to go a step further, they could look at the 9x23 Winchester for a semi-auto, but I'm not committed to that cartridge in my own pistols.

I often practice with the 130 gr. 38 super + P, in order to attempt to duplicate my range practice, as if I were shooting with 357 sig. This helps offset the price I would otherwise be paying for the 357 sig, over that of the cost for what I pay for the 38 super.

Markopolo, I enjoyed talking to you and Thanks for bringing Massad along; Tell him I said Thanks as well. I could talk a lot of how his articles help mold my own opinions about a few things, especially those involving the Miami Shootout, Lance Thomas, his four inch Python, and a few others.

I gotta go now; Thanks for the Chat. Maybe we can finally get off the 357 sig and talk on another gun topic we both share interest in. Thanks Again.

 

I've done just the opposite with my Glock 32. Converted 357 SIG to 40 S&W. I like them both and I think if I ever have to shoot someone (God forbid) they wouldn't know the difference between the two. In my gun at least, the 40 is a little more accurate. I use Double-Tap ammo in both calibers. Very potent stuff but accurate.

 

I've also done the same when purchasing one of my Sig Sauer P-229s. I bought a SIG factory .40 S&W barrel for it at the time of purchase.

One of my Sig 229 Sport pistols had to be sent off to the Sig Sauer factory, in order to have a .40 S&W threaded comp barrel fitted for it.