The case for the 357 Sig

The .357 Sig was developed as a collaboration between Sig Sauer and Federal Ammo. The effort was to produce a cartridge that could be fired from firearms chambered for .40 S&W and utilizing a different barrel duplicate the performance of the .357 Magnum 125 grain cartridge – let’s take a look at it and see how they did with it.

Let’s take a look at the cartridge . . .


Sig wanted to equal or exceed the performance level of a 357 magnum in a 125 grain bullet loading for a very good reason – 357 magnum /  125 grain bullet has the best one shot stop percentages of any handgun cartridge – 96 % – and that is from 1935 to the present ! I really don’t want to get into a long drawn out discussion on handgun stopping power – let’s just all realize handguns are not the best choice but it is difficult to tote a 12 gauge shotgun or an AR-10 or a Ma Deuce  Or here if you have about 30 minutes (really nice with a good sound bar and high volume level ) with you all the time in a discrete manner – thus handguns.

Sig and Federal Cartridge did very well with their project – average velocity of 357 magnum / about 1270 fps – average velocity of 357 Sig / 1350 – and yes, 80 fps is a significant difference. If you want to go exploring for yourself – let me point you in this direction – However – if in your digging through all the stuff – if you read ” well the 357 Sig is just a necked down 40 ” realize the writer is in error – being lazy – parroting what others are saying – take your pick. The case dimensions for the 40 S&W are SHORTER than the case dimensions for the 357 Sig. And if you start with a shorter case and then neck it down – that really doesn’t work – it comes out even shorter. And if your willing to spend a little bit more for food for your 357 Sig – try Underwood Ammo for this load – Oh My!

Let’s see – 125 grain projectile @ 1270 fps or 125 grain projectile at 1475 fps . 205 fps is an incredible difference in performance – about 16% more performance over a 357 magnum

I tend to go with bonded  jacketed hollow points when you start edging towards maximum loads in any bullet – handgun or rifle – normal jackets – cup and core construction – have a tendency to start to peel and sheer off – you start shedding projectile weight and then you’re shedding kinetic energy and penetration .

A great many of the comparisons between these two head straight to ” but the 357 magnum with 158 grain – or 180 grain – or . . . let’s compare apples to kiwi fruit – the endeavor undertaken was to equal or exceed 357 magnum in one bullet weight – 125 grain – and Sig and Federal Cartridge succeeded – and in my humble opinion did quite well.  And yes there are commercial offerings available in 135 grain and 147 grain but your trading bullet weight for velocity and edging away from that 125 Grain “sweet spot”.

If you want to go to a lighter bullet – there is this offering from Underwood Ammo – damn that’s into rifle velocities – might have to grab a couple of boxes just to play with!!

Utilization of existing platforms (where it starts making sense)  . . .

The base of the case is identical to the “40” – which means that any platform that runs “40” could run .357 Sig as well. Just a barrel swap and everything works – the breech face / the same – the extractor / the same – the ejector / the same – the magazine / the same – the recoil spring / the same – all you need to do is swap out the barrel and you have .357 Magnum performance out of a semi automatic pistol. From a manufacturing perspective just change the roll marks on the slide and drop in a different barrel and away you go.

Why should I care? – Or – I like my wheel gun!

Not to step too deep into the bucket of semi auto vs revolver, let’s look at the obvious – and try to avoid sentimentality – Let’s take this straight on – revolvers are cool no doubt about that – there is a romanticism about them that most auto loaders just don’t match – however full size revolvers are more difficult to conceal ( we are going to try to compare apples to apples as much as we can ) when comparing full size duty weapons – the width of the cylinders are quite bulky when compared to semi auto’s – the capacity is not even close to each other – 6 rounds for the revolver vs 15 plus 1 for a Glock 31 – and if you go to compare a J frame sized revolver vs a S&W Shield 40 with a 357 Sig conversion barrel – (Y’all think there might be review coming up on that conversion??) ( Yes Virginia, there is a Santa Claus ) – your down to a 5 shot capacity and a 2 inch or less barrel – which loses you sight radius and velocity – and to be honest about it I know of no one who fires hundreds of round of full power 357 magnum in a snub nose revolver to become and remain proficient with it. Nobody. And I hang around with a whole bunch of folks who shoot on a regular basis. Anybody that enjoys that level of abuse are usually too tied up to make it to the range. Heh-Heh.

So did they succeed?. . .

Quite well in my biased opinion – you have the equivalent of one of the best personal weapons cartridges in the business with the capability of an auto loading platform. Glock currently produces pistols in 357Sig – Sig produces a number of platforms as well – P226 and P229 as well as these 1911 platforms – though not being produced anymore there is a lot of Sig P239’s in 40 on the used market.

Sig 1911 Nightmare


Sig 1911 Tacops (which I am lusting after)


A whole bunch of more “stuff” coming up – maybe even a review or two on long guns – recipes – and even some truly impressive rifles. . .

Remember – Have Fun – Run the Gun – and Fish Heads are Cheap!!

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