38 and 357

[montveil]

A question that has me wonderin.
I figure a 38 and 38 special is 38 caliber
Why is a 357 mag able to fire 38 ammo-- is a 357 38 cal, and if so why is it called a 357?

[gb_in_ga]

It's a long story.

No, a .38 Spl is not really a .38 bore. It is actually a .357 bore. There is a long historical reason why it is called .38, having to do with the lineage of the round. I'm sure that someone will chime in with the full story, I'm almost certain to botch it.

And a .357 Mag actually is a .357 bore. It is an offspring of the .38 Spl, for that matter. The reason for there being a .357 Magnum is yet another fairly long story.

[madmag]

Anyone.

OK, a .38 is not .38 it's actually .357 dia. Long story, but this all came about because .38 started out as a black powder ball round. When .357 came on the scene (circa 1934) they called it by the correct diameter but made the casing longer so it would not fire in normal .38 spl. due to pressure strength requirements.

Bottom line. The .38 spl. is the same as .357 mag. except for case length.

Clear as mud?

Thanks gb, you got in while I typed.

[madmag]

http://guns.wikia.com/wiki/.38_Special

[oldgranpa]

+1
Try it yourself. A .357mag cartridge will not fit in a properly made .38special cylinder. But a 38 will fit in a .357mag revolver and fire ok.

[Dave85]

The developement ran like this:

Colt developed the .38 Short Colt that used a heel-based bullet which was actually around .38 caliber. The bullet was seated by a heel at the base (like a .22 LR).

Colt then developed the .38 Long Colt which seated the bullet entirely inside the cartridge as is the modern mode with centerfire cartridges. While the case diameter stayed at right around .38 caliber, the bullet was reduced to .361 to fit inside the case.

Smith & Wesson developed the .38 Special from the .38 Long Colt, with variances so slight in dimensions that the .38 Long Colt will work in the .38 Special. The bullet diameter was set at .357.

When Smith & Wesson later developed a Magnum cartridge based on the .38 Special, they decided, for reasons that are probably a matter of an entire discussion unto itself, to use the actual bullet diameter.

Now, I have a question for the others: I have called the bullet diameter .357, but is that the bore diameter? I have read in some sources that the bullets are .358.

EDIT: Just went to the Wikipedia page, and lo and behold, they have it listed with a diameter of .358.

[montveil]

WOW, what great explanations.
It seems that in the early 1900's the bullet/cartridge nomenclatures were rather varied and a lot carried over from black powder days and calender references
45/70, 3006, 3030 and the 38's 22 lr vs 223 etc
No wonder I was confused. thanks for the history lessons

Thanks

[gb_in_ga]

Now, I have a question for the others: I have called the bullet diameter .357, but is that the bore diameter? I have read in some sources that the bullets are .358.

The bore is .357, but the bullet diameter depends on the type of bullet. You use .357 jacketed bullets, but you use slightly larger .358 cast or swaged lead bullets in order to get a better seal and therefore less barrel leading.

[montveil]

As another thought whether the rifle bore is measured from the lands or grooves.
I have heard that 22 lr has the actual bullet diameter of .22 inches as it came from black powder heritage.
Newer bullets are measured from the lands such as 223 represents the bullet diameter from the bottom of the grooves

Do I have this mess roughly correct?

Thanks again

[gb_in_ga]

WOW, what great explanations.
It seems that in the early 1900's the bullet/cartridge nomenclatures were rather varied and a lot carried over from black powder days and calender references
45/70, 3006, 3030 and the 38's 22 lr vs 223 etc
No wonder I was confused. thanks for the history lessons

FYI, the practice hasn't really gone away. It just isn't as prevalent anymore.

For instance, take the case of the .357 SIG round. Is it a .357 bore? Nope. It is actually a "true" 9mm, a .355 bore. For marketing reasons it was called a .357 because it was intended to appeal to those who longed for their .357 Mag revolvers in an autoloader platform. Calling it .355 SIG (which would have been accurate) just didn't have the marketing appeal to the intended audience.