Vafighter07
Inactive
How can a 5.56x45 round have different grain weights? What does the 5.56x45 stand for? I use this round but could easily substitute any round.
Thanks
Vafighter07
Thanks
Vafighter07
Cartridge Question
- Thread starter Vafighter07
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Simple, the 5.56x45 NATO..
originally devised using the 55gr bullet and the slow twist rifling 1 rotation in 10 in of travel.
Due to report of poor penetration in the heavy bush of Viet Nam and the use of body armor by Warsaw Pact armies, the bullet was made heavier using a steel core, which now weighed 62gr. the twist was too slow for stabilization and that was changed to the 1:7.7 (or 8) twist.
With now the longer range use in the war on terrorism the weight for SOME round is 75gr.
the 5.56 X 45 in the NATO designation of the caliber [5.56mm or .223 inches] and the overall cartridge length [45MM or 1.77inches].
I shoot over the course hipower comptetition and use the 68gr match bullet.
originally devised using the 55gr bullet and the slow twist rifling 1 rotation in 10 in of travel.
Due to report of poor penetration in the heavy bush of Viet Nam and the use of body armor by Warsaw Pact armies, the bullet was made heavier using a steel core, which now weighed 62gr. the twist was too slow for stabilization and that was changed to the 1:7.7 (or 8) twist.
With now the longer range use in the war on terrorism the weight for SOME round is 75gr.
the 5.56 X 45 in the NATO designation of the caliber [5.56mm or .223 inches] and the overall cartridge length [45MM or 1.77inches].
I shoot over the course hipower comptetition and use the 68gr match bullet.
Info you seek
5.56 mm, is the metric equivalent of .223" thousandth's of an inch. The "x" means "by" and the 45 indicates the case length is 45 mm. Thus the cartridge is expressed as a "5.56 by 45 mm"
another example: 7.62mm equals .308" thousandths of an inch
6.00 mm equals .243"
7.00 mm equals .288"
chi-com ak-47 ammo: 7.62 x 39 = .308" bullet in a 39 mm long case
russian rifle ammo: 7.62 x 54r = .308" bullet in a 54 mm long case intended for use in a rifle.
Hope this answers your question & welcome to the forum family !!!
Guru1911
5.56 mm, is the metric equivalent of .223" thousandth's of an inch. The "x" means "by" and the 45 indicates the case length is 45 mm. Thus the cartridge is expressed as a "5.56 by 45 mm"
another example: 7.62mm equals .308" thousandths of an inch
6.00 mm equals .243"
7.00 mm equals .288"
chi-com ak-47 ammo: 7.62 x 39 = .308" bullet in a 39 mm long case
russian rifle ammo: 7.62 x 54r = .308" bullet in a 54 mm long case intended for use in a rifle.
Hope this answers your question & welcome to the forum family !!!
Guru1911
Welcome to TFL!
The terms used in ammunition descriptions are a blend of the specific and the general. And of US and European practices. Some cartridge names are very precise. Others bear only a general relationship to the actual dimensions of the round.
Some rounds have been in use well over 100 years, and their names reflect the customs of an earlier era. Others reflect the inventor's or manufacturer's idea of what would sell well. Still others are military designations, determined by governments.
It is a large, and interesting field and many good books have been written about cartridges and their names, and how they came to be what they are today.
But it can be very confusing until you learn the specifics of the rounds you are talking about, and the different terms for different features of their construction.
For instance...
The grain weight is the weight of the bullet in grains (Averdupois scale). In this scale, there are 7000 grains (gr) to the pound (lb).
Cartridges are loaded with slightly different weights of bullet, for different purposes or reasons. Heavier bullets do some things better than lighter bullets. Light bullets do some things better than heavier ones.
Most cartridges have at least two names, and some even more. Our Military calls the round the 5.56mm (aka 5.56x45 and 5.56mm NATO) In the US the round is also called the .223 Remington.
Be aware that the actual bullet diameter used in a given round may not be exactly the same as the dimension indicated in the name. It is usually close though. Some cartridges are named based on the diameter of the bore, others on the diameter of the groove to groove distance. For example;
A .30 caliber rifle is one that has a bore diameter of .300. But the groove diameter is commonly .308, or even .311-.312.
A .308 Winchester and a .30-06 both have bores of .300, and grooves of .308". The fire the same bullet (which is .308 dia) but their cases are different lengths. These two rounds in the European system are 7.62x51mm (.308Win) and 7.62x63mm (.30-06).
Confused yet?
It gets even worse when you talk pistol rounds!
also, FYI 7.62mm is .300", NOT .308" And the Russian rounds called 7.62 actually use a .311 or .312 bullet!
And so does the .303 British and the 7.7mm Japanese!
I know this seems kind of crazy, but once you do a bit of research you will see that there is actually a method to the madness. Mostly. sometimes....
Ask any specific question you want, we'll answer it the best we can.
The terms used in ammunition descriptions are a blend of the specific and the general. And of US and European practices. Some cartridge names are very precise. Others bear only a general relationship to the actual dimensions of the round.
Some rounds have been in use well over 100 years, and their names reflect the customs of an earlier era. Others reflect the inventor's or manufacturer's idea of what would sell well. Still others are military designations, determined by governments.
It is a large, and interesting field and many good books have been written about cartridges and their names, and how they came to be what they are today.
But it can be very confusing until you learn the specifics of the rounds you are talking about, and the different terms for different features of their construction.
For instance...
The grain weight is the weight of the bullet in grains (Averdupois scale). In this scale, there are 7000 grains (gr) to the pound (lb).
Cartridges are loaded with slightly different weights of bullet, for different purposes or reasons. Heavier bullets do some things better than lighter bullets. Light bullets do some things better than heavier ones.
5.56 stands for the bore size, in millimeters (mm), and 45 is the length of the brass case in mm. This is the common European system of designation. When read aloud it is said "5.56 by 45" mm
Most cartridges have at least two names, and some even more. Our Military calls the round the 5.56mm (aka 5.56x45 and 5.56mm NATO) In the US the round is also called the .223 Remington.
Be aware that the actual bullet diameter used in a given round may not be exactly the same as the dimension indicated in the name. It is usually close though. Some cartridges are named based on the diameter of the bore, others on the diameter of the groove to groove distance. For example;
A .30 caliber rifle is one that has a bore diameter of .300. But the groove diameter is commonly .308, or even .311-.312.
A .308 Winchester and a .30-06 both have bores of .300, and grooves of .308". The fire the same bullet (which is .308 dia) but their cases are different lengths. These two rounds in the European system are 7.62x51mm (.308Win) and 7.62x63mm (.30-06).
Confused yet?
It gets even worse when you talk pistol rounds!
also, FYI 7.62mm is .300", NOT .308" And the Russian rounds called 7.62 actually use a .311 or .312 bullet!
And so does the .303 British and the 7.7mm Japanese!I know this seems kind of crazy, but once you do a bit of research you will see that there is actually a method to the madness. Mostly. sometimes....
Ask any specific question you want, we'll answer it the best we can.
Sweet Shooter
New member
Not quite right actually. The first twists were 1x14 they were then tightened to 1x12. I think it went to 1x9 after that and then in some colts went back to 1x10. The 62gr shoots fine in all my 1x12s.
-SS-
thedaddycat
New member
There are other chamberings that use a different designation. The .30-30 Winchester and .30-40 Krag were at one time black powder cartriges. With these two examples, the first number (.30) means 30 caliber and the second number (-30 and -40) designate the black powder equivalent charge.
Thus a .30-30 is 30 caliber with a 30 grain black powder equivalent charge and the .30-40 Krag has a 40 grain black powder equivalent charge. These chamberings were at one time black powder metalic cartriges using either 30 or 40 grains of black powder, but with the advent of smokeless powders the power levels for safe use in older guns dictate using an amount of smokeless powder that equates to the given black powder charge.
It gets more interesting with the .30-06 and derivatives. The 1903 Springfield rifle and its cartrige,when first developed in 1903 by the Army at the Springfield Armory, used a different bullet but the round was updated and finalized in 1906. This designation stands for 30 caliber of 1906 and though it is often just called the .30-06 the full name is .30-06 Springfield. When the case was necked down to 25 caliber it was called the .25-06 because it was based on the .30-06 case.
One reason that the 1903 Springfield rifle was developed was for faster reloading. In the Spanish-American War, the .30-40 Krag rifle in use at that time had a magazine that opened on the right side and the rounds were more or less dumped into the box. It had a magazine cut-off to allow single shot firing and loading. The 7mm Mauser rifles had a slot milled into the receiver bridge that allowed the use of a stripper clip and it was much faster to reload and continue firing. The 1903 Springfield rifle did have the ability to use stripper clips.
Here are the 7mm Mauser (top) with the stripper clip slot shown and the .30-40 Krag-Jorgenson (bottom) with box magazine door open.
To directly answer your question, the grain weights usually listed are bullet weights. When reloading ammunition, the reloading tables will list powder charge weights in grains. These will vary with the powder used and bullet weight.
Thus a .30-30 is 30 caliber with a 30 grain black powder equivalent charge and the .30-40 Krag has a 40 grain black powder equivalent charge. These chamberings were at one time black powder metalic cartriges using either 30 or 40 grains of black powder, but with the advent of smokeless powders the power levels for safe use in older guns dictate using an amount of smokeless powder that equates to the given black powder charge.
It gets more interesting with the .30-06 and derivatives. The 1903 Springfield rifle and its cartrige,when first developed in 1903 by the Army at the Springfield Armory, used a different bullet but the round was updated and finalized in 1906. This designation stands for 30 caliber of 1906 and though it is often just called the .30-06 the full name is .30-06 Springfield. When the case was necked down to 25 caliber it was called the .25-06 because it was based on the .30-06 case.
One reason that the 1903 Springfield rifle was developed was for faster reloading. In the Spanish-American War, the .30-40 Krag rifle in use at that time had a magazine that opened on the right side and the rounds were more or less dumped into the box. It had a magazine cut-off to allow single shot firing and loading. The 7mm Mauser rifles had a slot milled into the receiver bridge that allowed the use of a stripper clip and it was much faster to reload and continue firing. The 1903 Springfield rifle did have the ability to use stripper clips.
Here are the 7mm Mauser (top) with the stripper clip slot shown and the .30-40 Krag-Jorgenson (bottom) with box magazine door open.
To directly answer your question, the grain weights usually listed are bullet weights. When reloading ammunition, the reloading tables will list powder charge weights in grains. These will vary with the powder used and bullet weight.
After a while, you will actually start to wonder if there ever was a system.
No, there never was a system. thousands of inventors in hundreds of different countries named cartridges according to their own personal ideas. As was mentioned, even the famous .44 magnum is not actually a .44 diameter bullet, nor is a .38 special a 38 caliber bullet. The .410 shotgun shell is actually the measure of the bore, but all other shells measured by gauge are measured by a lead ball. If a one ounce ball will fit in a shotgun bore, it is a 16 gauge. The gauge number is calculated by how many balls of the bore diameter add up to 1 pound. A 12 gauge bore diameter matches a lead ball that weighs 1/12th of a pound.
Keep asking questions. and unlike a lot of people here, I find that wikipedia is actually a pretty good resource to check with this sort of question.
No, there never was a system. thousands of inventors in hundreds of different countries named cartridges according to their own personal ideas. As was mentioned, even the famous .44 magnum is not actually a .44 diameter bullet, nor is a .38 special a 38 caliber bullet. The .410 shotgun shell is actually the measure of the bore, but all other shells measured by gauge are measured by a lead ball. If a one ounce ball will fit in a shotgun bore, it is a 16 gauge. The gauge number is calculated by how many balls of the bore diameter add up to 1 pound. A 12 gauge bore diameter matches a lead ball that weighs 1/12th of a pound.
Keep asking questions. and unlike a lot of people here, I find that wikipedia is actually a pretty good resource to check with this sort of question.
thedaddycat
New member
Scorch, Thank you for rectifying my error. I stand corrected.
While these two chamberings did in fact use the then common designation like that used on the .45-70 they were indeed both developed in the late 1800's as smokeless powder cartriges. I do not know if either one was the first smokeless cartrige developed, but they were among the earliest ones.
While these two chamberings did in fact use the then common designation like that used on the .45-70 they were indeed both developed in the late 1800's as smokeless powder cartriges. I do not know if either one was the first smokeless cartrige developed, but they were among the earliest ones.
tahunua001
New member
ok for a round break down 5.56mm is the bullet diameter,
x45mm is the casing size
the grain is referring to bullet weight, lead, copper, steel and plastic all have different weights for the same amount of material. a fmj will have less mass than a hollowpoint of the same surface area. so a 55gr bullet still has the same casing and bullet diamerter as a 62gr bullet, it's just different construction methods
x45mm is the casing size
the grain is referring to bullet weight, lead, copper, steel and plastic all have different weights for the same amount of material. a fmj will have less mass than a hollowpoint of the same surface area. so a 55gr bullet still has the same casing and bullet diamerter as a 62gr bullet, it's just different construction methods
And then there is the "year".
The first '06 round wasn't. It was a 30-03, or offically the 30 Cal US, then it was modified in 1906 to what we now call the 30-06.
We also have the 44-90 in several configerations as in the 44-90 BN which was a modified Remington 44-90 into a bottle neck case (BN). The 44-90 Remington was a buffalo cart. The 44-90 Bottleneck was designed for target shooting. Also chambered in the Remingtion Rolling block.
Confused even more: Look at the Remington Rolling Blocks, they were chamberd in several different rounds, but often Remington didn't put the cartrige listing on the barrel. On mine I had to do a chamber cast, and measurements with lots of research to find what I had.
Get a copy of CARTRIDES OF THE WORLD, it explains a lot.
The first '06 round wasn't. It was a 30-03, or offically the 30 Cal US, then it was modified in 1906 to what we now call the 30-06.
We also have the 44-90 in several configerations as in the 44-90 BN which was a modified Remington 44-90 into a bottle neck case (BN). The 44-90 Remington was a buffalo cart. The 44-90 Bottleneck was designed for target shooting. Also chambered in the Remingtion Rolling block.
Confused even more: Look at the Remington Rolling Blocks, they were chamberd in several different rounds, but often Remington didn't put the cartrige listing on the barrel. On mine I had to do a chamber cast, and measurements with lots of research to find what I had.
Get a copy of CARTRIDES OF THE WORLD, it explains a lot.
tahunua001
New member
haha oops, I said that backwards, a FMJ will have MORE mass than a hollowpoint of equal surface area
Cartridge designation , numbers and naming follows no rhyme or reason. The numbers aren't alway 'right' either.
.30 caliber!
Some use pre-rifling bore dia , some use groove/bullet dia.
A .300dia hole + .004rifling depth = .308
The .300 Savage , 7.62x51 NATO and 7.5x55 Swiss all use a .308 dia bullet , yet the 7.62x39 AK round and 7.62x54R (R means Rimmed , not rifle or Russian) uses a .310-.311dia bullet. Yet the decimal equivilant of 7.62 = .29997.
It get's worse.
The .380 ACP and 9mm Luger both use a .355 dia bullet. The 9mm Makarov uses a .364.
The .38 Special and .357 Magnum both use .357dia bullets.
The .38-40 Winchester uses a .401 dia bullet. The 44-40 uses a .427.
The .44 Special and .44 Magnum use a .429dia bullet.
The .45 Colt , .454 Casull and .460 S&W all use a .451 dia bullet
A .270 Winchester uses a .277dia bullet. Yet .277 is the actual decimal equivelant of 7mm.
The 7x57 Mauser , 7mm-08 , .280 Remington and 7mm Remington Magnum both use a so-called 7mm bullet , actually a .284 dia bullet.
The .218 Bee , .219 Zipper , .220 Swift , .221 Remington Fireball , .222 Remington Magnum , .223 Remington(5.56x45) , .224 WeatherbyMagnum and .225 Winchester all use a .223 dia bullet.
.30 caliber!
Some use pre-rifling bore dia , some use groove/bullet dia.
A .300dia hole + .004rifling depth = .308
The .300 Savage , 7.62x51 NATO and 7.5x55 Swiss all use a .308 dia bullet , yet the 7.62x39 AK round and 7.62x54R (R means Rimmed , not rifle or Russian) uses a .310-.311dia bullet. Yet the decimal equivilant of 7.62 = .29997.
It get's worse.
The .380 ACP and 9mm Luger both use a .355 dia bullet. The 9mm Makarov uses a .364.
The .38 Special and .357 Magnum both use .357dia bullets.
The .38-40 Winchester uses a .401 dia bullet. The 44-40 uses a .427.
The .44 Special and .44 Magnum use a .429dia bullet.
The .45 Colt , .454 Casull and .460 S&W all use a .451 dia bullet
A .270 Winchester uses a .277dia bullet. Yet .277 is the actual decimal equivelant of 7mm.
The 7x57 Mauser , 7mm-08 , .280 Remington and 7mm Remington Magnum both use a so-called 7mm bullet , actually a .284 dia bullet.
The .218 Bee , .219 Zipper , .220 Swift , .221 Remington Fireball , .222 Remington Magnum , .223 Remington(5.56x45) , .224 WeatherbyMagnum and .225 Winchester all use a .223 dia bullet.
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Vafighter07
Inactive
Thanks
What great information! I appreciate all the answers and had my question answered many times over.
What great information! I appreciate all the answers and had my question answered many times over.
Major Dave (retired)
New member
Back to your original question
namely, how can (name any cartridge) have different grain weight bullets?
Generally speaking, all cartridges have different grain weight bullets, though a few have only 2 or 3.
HOW? - you ask. By the simple expedient of making the bullets longer, or shorter.
Your beloved .223 Rem/5.56mm NATO, according to one hand loading manual shows bullet weights of (are you ready?):
36, 40, 45, 50, 52, 55, 60, 63, 69, 75, 77, and 80 grains!
The lightest bullets can be hand loaded to over 3,700 fps muzzle velocity (for shooting prairie dogs and other small pests), while the heavy ones can be loaded to about 2,800 fps MV, for deer hunting.
A slow rifling (1 turn per 12 inches) twist barrel is best for accuracy with the light/short bullets, and a fast (1:7 inch) twist is best for the heavy/long bullets. This is true regardless of which caliber you are shooting.
Good shooting.
namely, how can (name any cartridge) have different grain weight bullets?
Generally speaking, all cartridges have different grain weight bullets, though a few have only 2 or 3.
HOW? - you ask. By the simple expedient of making the bullets longer, or shorter.
Your beloved .223 Rem/5.56mm NATO, according to one hand loading manual shows bullet weights of (are you ready?):
36, 40, 45, 50, 52, 55, 60, 63, 69, 75, 77, and 80 grains!
The lightest bullets can be hand loaded to over 3,700 fps muzzle velocity (for shooting prairie dogs and other small pests), while the heavy ones can be loaded to about 2,800 fps MV, for deer hunting.
A slow rifling (1 turn per 12 inches) twist barrel is best for accuracy with the light/short bullets, and a fast (1:7 inch) twist is best for the heavy/long bullets. This is true regardless of which caliber you are shooting.
Good shooting.
No, they all shoot .224 diameter bullets.
The .22 long rifle is .223 as are some very early rifles chambered for the .22 Hornet, mostly because they used rechambered rimfire barrels to make the early .22 Hornet rifles.
Current .22 Hornets have .224 grove diameter barrels just like the rest of the centerfire .22's.
Jim Watson
New member
It is not that there is no system, it is that there are several different ones and you just have to learn to recognize what you are looking at.
Cartridges of the World (CotW) is a book worth having, even though it doesn't have every single cartridge ever made. (Recent thread about the .45-80 Sharpshooter Trapdoor Springfield not well known.)
Cartridges of the World (CotW) is a book worth having, even though it doesn't have every single cartridge ever made. (Recent thread about the .45-80 Sharpshooter Trapdoor Springfield not well known.)
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