Please explain the difference between .38 and .380 (vanity)

2/16/03 | self

[rudy45]

I had always believed that the caliber of a gun was the inside diameter of the barrel. Assuming I am correct (am I?) then shouldn't .38 and .380 be "close"? If I remember from high school math, the latter simply implies a greater degree of precision. IOW, a .38 caliber really could be anything from .376 to .384, while .380 caliber has smaller variance--.3796 to .3804?

However, the attendant at a local range said that .38 refers to revolvers while .380 refers to pistols (?)

Thanks.

[Bogey78O]

I would've guessed rifles not pistols.

[Indrid Cold]

380 is a "9mm short"; the same bullet with less powder behind it, for semi-auto pistols. .38 is a revolver cartridge with more powder behind it than the .380. I don't think the bullet is the same, but yeah, the diameter is real similar. .38 curiously has the same diameter as the .357 (magnum).

[SevenDaysInMay]

Buy a reloading manual or better two. Hornady and Nosler have superb basics explanations with lots of graphics and specs on most current popular choices.

This is the sort of information which citizens must carry into the next Democrat fascist administration.

[Servant of the Nine]

Actually, the "38" is a .35.
Dont let it bother you, it's an old problem rising from the way cartridges were measured when they were invented.

A .38 or a .357 magnum are both .357. The .357 case is longer, and holds more powder for more power.

The .380 is a european calibre. It is actually called 9mm kurtz. it is .355 just like the longer more powerful 9mm parabellum (9mm Luger).

Dont even think about the other members of the family like the .38 Super or .357 SIG. That is when it gets very complicated.

SO9

[Ches]

Bang!

[JRandomFreeper]

I carry a .380 autoloader and my dear spouse carries a 9mm. I use the same press to reload our ammo. The same bullet is used with a different case.

The .380 and 9mmm are rimless cases for autoloaders. The .38 is a rimmed case that (typically) fires from wheel-guns.

The ballistics are completly different from one round to the other.

/john

[11th Earl of Mar]

Thanks for the details.

Now can you explain the nine-tenths of a cent added to every gallon of gas?

[c-b 1]

The main difference is in the length of the case, the .380 case is approximately 5/8 inch long, the .38 case is approximate 1 1/8 inch long. The configuration of the case is also slightly different. A .380 bullet could be loaded into .38 brass, but a .38 bullet should never be loaded into .380 brass because of the slightly larger diameter of the .38.

[templar]

A .38 usually refers to the 38 special, cartridge length of 1.155 inches, overall loaded length of 1.55, usually a 158 grain .357 diameter bullet at around 750 fps.
A .380 is a smaller round, cartridge length of .680, overall loaded length of .984, bullet diameter of .355, usually a 100 grain bullet about 950 fps.

Similar bullet diameters are found in the 9mm luger, 9mm largo, .357 magnum, 38 automatic, 38 super automatic, 38 Smith & Wesson (which is the largest bullet diameter at .360), and a few rare old cowboy and BP guns.

None of these have an actual .380 bore, most are .355, .357, or .360.

[Oschisms]

So a .380 will take 9mm ammo? Sorry for my ignorance.

Going to bed now- will thank you tommorrow.

[JRandomFreeper]

usually a 158 grain .357 diameter bullet at around 750 fps.

Now, explain +P loads. ;>)

/john

[dts32041]

Yeah, I could but then I would have to kill you. :-)

[absalom01]

This should bring the handloaders out on a slow news night..

The souce of your confusion is in thinking of the numerical designation as a strict caliber, or bullet diameter (actually, the dimension between the grooves of a rifled barrel, but that's more detail that you asked after.)

These are cartridge designations -- properly, the .38 Smith & Wesson similar to the .38 special, aka the .38 Smith & Wesson Special, designed by that company, and for years a standard cartridge for police in the US. The case diameter is .379", with a bullet diameter of .357". (As a poster above noted, this is the same case diameter as the .357 Magnum, more properly known as the .357 S&W magnum.) IOW, you can use a .38 S&W Special cartridge in a .357 Magnum revolver, but not the other way around. Also, since this was designed for a revolver, it has a "rimmed" case, ie, a pronounce lip that sticks out at the bottom of the cartridge, to keep the rounds from falling out of the cylinder when you load them.

The .380, on the other hand, was designed for semi-auto handguns, and thus uses a 'rimless' case. (OK, I know that there are semi-autos out there chambered for rimmed ammunition, but that's too esoteric for this post.). Interestingly enough, this cartridge is most commonly referred to in this country as the .380 ACP (Automatic Colt Product/Pistol), but is also referred to in reloading manuals as the 9mm Corto, 9mm Kurtz, and, in English speaking countries, the 9mm Short. It has a case diameter of .374, and a .355 diameter bullet.

This is a long way round of saying that your friend at the range gave essentially correct information, but left out all of the extraneous detail that would let you understand the answer, rather than accepting it blindly.

BTW, you don't have to take my word for it. The information above comes from the Lyman Reloading handbook (happened to be closest), 47th edition.

Regards,
Absalom

[JRandomFreeper]

So a .380 will take 9mm ammo?

No, the 9mm won't feed. But you can feed .380 in a 9mm. Bad idea. Always double check your ammo and weapon. And don't assume your wife grabbed the correct box out of the truck.

/john

[JRandomFreeper]

but that's too esoteric for this post.

Nothing is too esoteric for someone that has approached us for information. Explain about the Sig .357 autoloader. Because I don't understand why they did that. ;>)

/john

[Blue Leader]

"Explain about the Sig .357 autoloader. Because I don't understand why they did that."

It's quite simple, it's marketing. Sig wanted a cartridge that could captitalize on the reputation of the venerable .357 mag. It's not a .357 and it's not a magnum but it is a good cartridge.

[sd-joe]

The term caliber is actually used in two different ways.

In the original, it was refering to the diameter of the bullet (and the bore of the gun).

However, as companies brought out different ammunition based on approximately the same diameter bullets, it became necessary to tell them apart. Thus an approximate diameter designation was added to other descriptive words or numbers to identify a cartridge (the combination of bullet and case and powder charge and primer).

Thus the common 380 is designated the 380 ACP (ACP standing for Automatic Colt Pistol, I believe). The 380 cartridge is designed for semi-automatic pistols (not revolvers).

The most common 38 is actually the 38 Special. It is designed for revolvers.

The 380 ACP actually has a bullet diameter of .355. (That is just the way it was designed back in 1908).

The 38 Special actually has a bullet diameter of .357. (It was designed in 1902 as an improvement of the 38 Long Colt cartridge.

[harpseal]

indexing

[Shooter 2.5]

If you're interested in cartridges and you have no intention of reloading, try to find a copy of "Cartridges of the World". It has been the Bible of gun enthusiasts since they printed the first copy around the late Sixties.