....why a 9mm chamber can stand more pressure and get more speed than a .38. given equal bullet weights.

"But standard pressure 9×19 Parabellum have a SAAMI rating of 35,000 psi (more than double the pressure standard .38 Special loads can handle), and higher pressure +P loads can go as high up as 38,500 psi (also more than double the pressure the .38 Special +P can handle)."

'however, 38SPL has a case capacity of 23.4 grams H2O while 9mm has a case capacity of 13.3 grams H2O. that’s about half as much."

With larger case (and powder) capacity, why doesn't the .38 outperform. What about in an indestructible .357 Blackhawk?

The case capacity is 1.759 more for the .38.

It is not a matter of a .38 Special chamber not being able to withstand 9mm pressure; it is a matter of standards.

The .38 Special was originally a black powder cartridge, which explains both its relatively large case capacity as well as its moderate SAAMI pressure specification.

You absolutely could load a .38 Special case to 9mm pressures, or even .357 pressures, but doing this in an old revolver might not end well.

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Mark Lathem

I guess what he is asking is: IF the metal case of the .38 Special were of a stronger material, than it could have more powerful propellant in the case and the .38/9mm bullet "could" be more powerful--as the case would be double the capacity of the 9mm case.

No, he's talking case capacity only and I agree with his wonder.

It can but then you have to call it a 357 Magnum.

The 9x19 & 357 Magnum operate at essentially the same maximum pressures but with more powder the 357 easily outperforms the 9x19 using a 125gr bullet from the same barrel length.

.

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Waiting for the break of day

I agree but think about it from the other direction. It is not about what the round can produce but what the weapon can withstand. 38 SPL specs were set a long time ago with less robust firearms. To keep those same specs, modern 38 spl rounds have to be effectively "downloaded" from their potential.

SAAMI downloading ammo for older weapons is extremely common. They've done it for many Eurpean calibers, sometimes with good reason, and other times not so much. The classic example is what is loosely called 8mm Mauser. SAAMI is concerned that somebody would slap some fullhouse, WWII spec 196 gr, .323" rounds in an unmodified Commission Rifle with a .318" bore. SAAMI believes the average civilian buyer will be ignorant of how the Germans changed the spec. Sadly, they are largely correct.

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Release the Kraken

7x57 Mauser is another example. Comparing the load data to 7mm-08 drives me nuts. The 7x57 has considerably more case capacity but is loaded 200-300 fps slower. I have been told that it’s because of ‘93 and ‘95 Mauser rifles. SAAMI specs maximum average pressure of 51,000 psi. However, the European standard CIP specifies 56,564 for the 7x57 Mauser cartridge. Given that the vast majority of modern rifles (i.e. 20th Century) chambered in 7x57 Mauser also were chambered in .30-06 this “prudence” on SAAMI’s part seems stupid to me.

Similar argument for the 6.5x55 compared to the 6.5 Creedmoor. The Swede trounces the Creed when operating at the same pressures. Of course modern bolt guns like the Tikka can easily handle that pressure. The old Krags? Maybe...maybe not.

I would like European data for the 7x57. I have some Norma ammunition that's hot. It has snappy recoil and it hits a full 3" higher at 100 yards than the Federal 175 grain ammo I have. The velocities aren't given on the Norma box, but they are given on the Federal and they are surprisingly similar to 30-30 ammo. But, the federal still kills deer and has almost no recoil, so I shouldn't complain. But I'm sure my BRNOs could handle something a little more robust.

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"Free dirt, you dig."

Here’s a bit of Norma 7x57 data

7x57 MAUSER | Reloading Data for hand loading ammunition | Norma

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R/S
J.D.

The 38 Special case is capable of being loaded far hotter than today's 38 Special or 38 Special +P loads. Back in 1930, S&W introduced the .38-44 HD, which propelled a 158 grain bullet to an advertised 1125 fps. This ammo was intended to be used in N-frame revolvers chambered in 38 Special, but I have to wonder how many people shot this ammo through K-frame 38's? Anyone ever hear of people blowing up K-frame 38 Special revolvers because they used .38-44 HD ammo?

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VCDL, GOA, NRA

The 38 Special was an original Black Powder loaded round ... it needs the large case capacity to hold a decent charge of black powder ...Same thing goes for 45 Colt ... original load with black powder ... Large Case was required .

9mm Luger and 45 ACP ... much smaller because they were developed with Smokeless Powder...Never loaded with black powder ... the charge of smokeless is much smaller than black ... so the cases of 9mm and 45 acp are half the size !

I don't know about pressure .
Gary

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Certified Cajun
NRA Member

Actually, that was done. Many 1888 Commission rifles were modified to fire the later 7.92x57JS cartridge during WWI. All that was involved was simply increasing the chamber neck diameter slightly to accept the larger diameter JS bullet. The smaller bore diameter of the 1888 barrel was not a problem, the JS bullet just squeezed down. I once had a modified 1888, and I fired lots of WWII German 7.92x57JS ammunition in it without incident.

Regarding the .38 Special, it was indeed originally designed for black powder, and that is why its case capacity is so large. And in fact, there were black powder .38 Special factory loads still being made and sold well into the 1930s. Today, with smokeless powder the .38 Special could be loaded to develop far higher chamber pressures than it now does, except for all of the older revolvers in questionable condition still in use.That is why the .38-44 loads were developed in the 1930s. Basically, just a more heavily loaded and higher pressure .38 Special. It is even possible to get .357 Magnum performance using .38 Special cases, but that not recommended.

The strength of the brass is minimal compared to the strength of the steel surrounding the case.

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Front sight and squeeze

The strength of the case is largely immaterial. The strength of the cylinder/chamber is what matters. But that is a separate topic.

...the .357 was developed. Elmer Keith early on realized that with smokeless powder the potential of the .38 Special was much greater than the black powder loading. However, the revolvers needed a little more beef.

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"He was kinda funny lookin'"

Skeeter Skelton wrote a lot about loading higher pressure .38 Specials for use in .357 guns. Basically .357 loads in .38 brass. Brass does matter, but not as much as the gun. I've also trimmed .357 brass to .38 length. But be careful where you go with this. It's mostly uncharted territory so you're on your own.

My Friend, The .357

SAAMI standards? We don't need no stinking standards!

Attached Images

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Live long and prosper

Indeed, which was why I specified an unmodified Commission rifle in my post.

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Release the Kraken

The 1888 was one of many guns I wish I had kept. I have seen none for a very long time. I believe mine went to the Turks during WWI. It had some crescent-shaped stampings in several locations, plus an “S” stamped on the front receiver ring. That indicated the chamber conversion to use the S bullet.

I have a Gew 88, S marked, and a matching Kar 88, not S marked. The Gew 88 came as part of a bulk deal and needs a stock repair at the wrist. It's buried in the safe, but I think it has been Turked. The Kar 88 must have been used with some horrid ammo long ago as the bore is ugly. Doesn't help that the lands of the rifling are extremely narrow. Oddly, the metal outside just has patina, and a host of unit marks.

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Release the Kraken