I'm new to all of this, and I'm a bit confused about why .38 spl and .357 mag bullets/barrels are actually the same diameter. Are they actually .38 inch or .357 inch or neither? I'm guessing that there is some funny historical reason for this, which I would love to know. I also read in a recent post that .44 isn't really .44 inch. Are other calibers loosely named like this? Thanks for your insight.
Why are .38 spl and .357 mag the same diameter?
- Thread starter baj
- Start date
I agree. It is very frustrating. Especially to someone who is new to the hobby. 38 Special and 357 Magnum both employ projectiles that measure .357. You can use 38 Special ammo in 357 revolvers but not vice-versa. As I am sure you are finding out, the name of the cartridge may or may not give you the true dimensions of the bullet. A good example of this is 357 Sig, which actually launches a 9mm(.355) projectile. 44 Magnum revolvers fire bullets of both .429 and .430 measurement. Get yourself a copy of Cartridges of the World. It will give you in depth descriptions of every cartridge imaginable. It is a must for anyone who is into shooting. Have fun with it. And hang in there . You will get used to the different nomenclatures.
.38 refers to case dimensions. .357 refers to actual bullet dimensions. Why? Probably because .357mag sounds better than .38mag. Marketing at its best. A .44mag is really only .429 or .430, so it should be called a .43mag, but that doesn't sound as cool. A .45acp is really .452. A .444 Marlin is just a .429 bullet with a really thick case. And on, and on, and on.....
Mike Irwin
Staff
The quick answer is.... Marketing.
When S&W introduced the .357 Magnum in the 1930s, they wanted a catchy name that differentiated it from its older parent, the .38 Special.
The .38 Special, developed in the 1890s, was actually a variation not on the existing .38 Smith & Wesson round, but on the then-military-standard .38 Long Colt.
The .38 Long Colt, when it was first introduced, actually DID use a true .38 caliber bullet, called a heeled bullet.
A heeled bullet looks, in profile, something like a mushroom, with a larger cap (which was .38 caliber), sitting on top of a smaller diameter shank, or heeled section. The heel fit inside the case mouth. When the bullet was seated, the outside diameter of the bullet and the outside diameter of the case were the same.
The heeled portion of the bullet was, .357 or so in diameter.
Starting sometime in the late 1880s many ammunition companies realized that the heeled bullet cartridge was hard to put together and had other disadvantages, such as the bullet lubricant being on the exterior of the bullet.
The decision was made to reduce the diameter of the bullets to a uniform diameter that matched the shank portion, in the case of the .38 Long Colt, that was .357, and in the case of many of the early .44s, such as the .44 Russian, that was .429.
The new bullet design had a lot of advantages, including lubrication grooves that could be seated inside the case mouth (making for much cleaner ammunition) as well as being easier overall to manufacture.
I've never found a good indication of whether the .38 Spl. was ever offered with heeled bullets, but I don't think that it was. I believe that it was one of the, if not the, first cartridges originally loaded with the new style bullet.
The only surviving members of the heeled bullet age are the .22s, Short, Long, & Long Rifle. If you pull a bullet out of a .22 Long rifle, you'll see very clearly what a heeled bullet looks like.
Finally, as for your question "are other cartridges named as loosely as this?"
The answer to that can best be summed up with...
"Oh my God, practically all of them!"
When S&W introduced the .357 Magnum in the 1930s, they wanted a catchy name that differentiated it from its older parent, the .38 Special.
The .38 Special, developed in the 1890s, was actually a variation not on the existing .38 Smith & Wesson round, but on the then-military-standard .38 Long Colt.
The .38 Long Colt, when it was first introduced, actually DID use a true .38 caliber bullet, called a heeled bullet.
A heeled bullet looks, in profile, something like a mushroom, with a larger cap (which was .38 caliber), sitting on top of a smaller diameter shank, or heeled section. The heel fit inside the case mouth. When the bullet was seated, the outside diameter of the bullet and the outside diameter of the case were the same.
The heeled portion of the bullet was, .357 or so in diameter.
Starting sometime in the late 1880s many ammunition companies realized that the heeled bullet cartridge was hard to put together and had other disadvantages, such as the bullet lubricant being on the exterior of the bullet.
The decision was made to reduce the diameter of the bullets to a uniform diameter that matched the shank portion, in the case of the .38 Long Colt, that was .357, and in the case of many of the early .44s, such as the .44 Russian, that was .429.
The new bullet design had a lot of advantages, including lubrication grooves that could be seated inside the case mouth (making for much cleaner ammunition) as well as being easier overall to manufacture.
I've never found a good indication of whether the .38 Spl. was ever offered with heeled bullets, but I don't think that it was. I believe that it was one of the, if not the, first cartridges originally loaded with the new style bullet.
The only surviving members of the heeled bullet age are the .22s, Short, Long, & Long Rifle. If you pull a bullet out of a .22 Long rifle, you'll see very clearly what a heeled bullet looks like.
Finally, as for your question "are other cartridges named as loosely as this?"
The answer to that can best be summed up with...
"Oh my God, practically all of them!"
There used to be a hot loading of the .38 special called the 38/44 designed for use in Smith N-frames. Trouble was that people would use it in the smaller K-frames and quickly do them in. Smith designed a 0.1" longer case (by stretching the .38 special) called the .357 Magnum that was only chambered in N-frames. The new cartridge had a chamber pressure almost double the .38 special. You can use .38 specials in a .357 magnum when you want reduced loads. This all took place back around 1935.
After WW2 with the advent of better heat treatment and improved metallurgy revolvers in the smaller K and J frames became available.
After WW2 with the advent of better heat treatment and improved metallurgy revolvers in the smaller K and J frames became available.
Experienced shooters used to handload .38 Special cases to what today we would call .357 Magnum velocities and pressures and fire them in N frame Smith & Wessons and .45 frame Colt revolvers, These loads were safe in those revolvers. Cartridge companies were afraid to duplicate these loads for fear they would be used ln lighter frame .38 Specials. The >357 Magnum case was produced by lengthening the .38 Special case so that it would not chamber in the cylinder of a .38 Special revolver/
The .357 is just a longer, hotter .38.
There once was a cartridge called the .38-44. It was just a .38 Special, loaded hot. The -44 indicated it should be used on the .44 frame.
The .357 name designation serves a safety purpose: the uninitiated are less likely to try to shoot it in an old .38 (don't assume .357s won't fit into some old .38s).
There once was a cartridge called the .38-44. It was just a .38 Special, loaded hot. The -44 indicated it should be used on the .44 frame.
The .357 name designation serves a safety purpose: the uninitiated are less likely to try to shoot it in an old .38 (don't assume .357s won't fit into some old .38s).
Guy B. Meredith
New member
I thought that some of the discrepancy in bullet names vs actual diameters in part came from whether the barrel of that caliber is measured across the grooves or the lands.
Tom Matiska
New member
Might as well mention the old 38-55 Winchester, which uses a .375 bullet.
Tom
Tom
Mike Irwin
Staff
Guy,
You're correct, for some cartridges the land/groove measurement DOES come into play, but not for the .357 Mag./.38 Spl.
A good example is the .300 Savage & .308 Winchester. Very similar cartridges, and both use a .308 diameter bullet.
In the case of the .300 Savage, the measurement is that across the lands, in the .308 Win., it's the measurement across the grooves.
Quite frankly, the system of cartridge nomenclature that is most logical and conveys the most information about the cartridge is the metric system used in Europe (and for American military firearms), which uses the nominal bullet diameter and the nominal case length, both expressed in milimeters.
But even in the European system there's fudge in how the bullet diameter is measured.
You're correct, for some cartridges the land/groove measurement DOES come into play, but not for the .357 Mag./.38 Spl.
A good example is the .300 Savage & .308 Winchester. Very similar cartridges, and both use a .308 diameter bullet.
In the case of the .300 Savage, the measurement is that across the lands, in the .308 Win., it's the measurement across the grooves.
Quite frankly, the system of cartridge nomenclature that is most logical and conveys the most information about the cartridge is the metric system used in Europe (and for American military firearms), which uses the nominal bullet diameter and the nominal case length, both expressed in milimeters.
But even in the European system there's fudge in how the bullet diameter is measured.
Mike Irwin
Staff
Quiet guy,
Funny you should mention the .41 Mag.
I loaded 100 rounds of .41 Mag. last night for a trip to the range tonight.
Funny you should mention the .41 Mag.
I loaded 100 rounds of .41 Mag. last night for a trip to the range tonight.