Please forgive a silly question

[sonofd]

Unless I missed math class, .38 of an inch is bigger than .357 of an inch. Am I missing something???

 

[Bunnykid68]

Not that I can see but I bet you have another question

 

[leftsock]

Not all calibers are measured equally, and sometimes the "name" of a caliber isn't always the size of the bullet.

.38 Special - Wikipedia, the free encyclopedia

Despite its name, the caliber of the .38 Special cartridge is actually .357–.358 inches (9.0678 mm), with the ".38" referring to the approximate diameter of the loaded brass case.

.357 Magnum - Wikipedia, the free encyclopedia

Though .38 and .357 would seem to be different diameter chamberings, they are in fact identical. 0.357 inch is the true bullet diameter of the .38 Special cartridge. The .38 Special nomenclature relates to the previous use of heeled bullets (such as the .38 Short Colt), which were the same diameter as the case. Thus, the only external difference in the two cartridges is a slight difference in length, solely for safety purposes as explained below.

 

[leftsock]

It gets even more fun if you start shooting black powder. Round ball calibers usually aren't the actual size of the projectile. They're usually slightly larger or slightly smaller, depending on what you're shooting.

 

[sonofd]

Not all calibers are measured equally, and sometimes the "name" of a caliber isn't always the size of the bullet.

.38 Special - Wikipedia, the free encyclopedia



.357 Magnum - Wikipedia, the free encyclopedia

Excellent. I can't thank you enough!

 

[Leo]

The .22 rimfire is the last heel based bullet that we commonly use. At the beginning of brass cartridge development, lots of calibers were heel base design.

To make it more interesting, the .380 acp is also called the 9mm kurtz in german lingo. this roughly means 9mm short, and it's bullets are about .355.

Good question.

 

[LANShark42]

The .22 rimfire is the last heel based bullet that we commonly use. At the beginning of brass cartridge development, lots of calibers were heel base design.

To make it more interesting, the .380 acp is also called the 9mm kurtz in german lingo. this roughly means 9mm short, and it's bullets are about .355.

Good question.

AKA 9x17...

 

[danielson]

This is prevalent in all firearms. Even the paintball guns I used to have. All the paintballs were ".68 caliber", but if you wanted decent accuracy, you needed to have a barrel kit, to match the ACTUAL size of the ball.

 

[Mgderf]

It's that "new math" you keep hearing about.

Must be time to go back to school!

 

[Gadgetmonster]

Great question. Good info. Thanks

 

[Shots fired...]

I learned something here as well. Thanks for asking!

 

[jwh20]

Unless I missed math class, .38 of an inch is bigger than .357 of an inch. Am I missing something???

Welcome to the world of totally inconsistent caliber "standards".

This is where .38 SPL = .357 Magnum = .380 ACP = 9mm ... All these (and probably some others I am not aware of) are all essentially the same diameter projectile.

 

[Constructionist]

While I've known the .38/.357 thing for a while now, I never knew the history behind it. Nor had I ever heard the heel-based diameter information either. This just goes to show how much I have yet to learn. OP, you led me to two new lessons today. Thank you.

 

[boogieman]

To make it more interesting, the .380 acp is also called the 9mm kurtz in german lingo. this roughly means 9mm short, and it's bullets are about .355.

.

Isnt the 380 also known as a 9x17 and 9mm browning?

 

[SSGSAD]

Unless I missed math class, .38 of an inch is bigger than .357 of an inch. Am I missing something???

Also, .44 Spl., and .44 Mag., are not .440, they are .429, same reason, heeled bullets, long time ago .....

 

[Bennettjh]

ACTUAL bullet size is very interesting/confusing. I think sometimes the designer of the bullet just picks a close number that sounds cool.. For instance, .357 Magnum.

 

[Spike_351]

I think the .357 and .38 share the same bullet diameter of 0.358, or at least every 38./.357 I have loaded has. The 40 S&W and 10MM are both 0.400 and when reloading you can use the same bullet for both calibers.

 

[You'll shoot your eye out]

The explanation that I received as a child from my father was this, Back in the day of muzzle loaders 36 caliber was common. Now .36 ball plus patch obviously is greater than .36. A .38 bore accommodates the .36 ball and patch, so a 36 caliber muzzle loader has a .38 bore. Now we bring in fixed cartridge guns. the traditional projectile for the 38 bore handgun was .36, but by this time the gun was called .38 because of the old patched bore sizes.

For the .36 projectile to engage a rifled barrel calls for yet another adjustment to .357, the current spec for a "38 caliber" barrel. Your .38 is in reality a .36 plus the reduction required to spin the bullet. The technical truths and reality was for nerds and public perception and commercial marketing was for the common man, thus the name .38 caliber was adopted for a plainly (and quite traditional) .36 caliber pistol

This is a dim memory from a conversation 45 years ago so the "experts" can save the rebuttals, I don't care.

 

[Indy_Guy_77]

Let's talk about all the "9mm" handgun cartridges!

9x19 = 9mm Parabellum = 9mm NATO = 9mm Luger
9x18 = 9mm Makarov = 9mm Mak
9x17 = .380 ACP = 9mm Kurz = 9mm corto = 9mm Browning = 9mm short
.38 ACP = .38 Auto (parent to the cool .38 Super)
.357 Sig
9x21
9x23 Largo
9x23 Winchester
9x23 Steyr = 9mm Steyr
9x25 Dillon
9x29 = 9mm Winchester Magnum

AND THEN there are the "9mm" revolver rounds!

9mm Federal
9mm Japanese
.38 Short Colt
.38 Long Colt
.38 Special = .38 S&W Special
.357 Mag = .357 S&W Magnum
.357 Max = .357 Remington Maximum
.38 S&W (Don't confuse this with .38 Special!)
.380/200 = .380 Revolver


And, honestly, nothing but reference material and wrote memorization will keep it all straight in your head.

And if you think there are lots of similar handgun cartridges - you don't even want to think about learning "all" the rifle cartridges out there...

 

[opus1776]

Also, .44 Spl., and .44 Mag., are not .440, they are .429, same reason, heeled bullets, long time ago .....

But! a .41 magnum has a .410 inch bore...


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