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kAnJii
08-11-2010, 11:16 PM
Speaking in a non-scientific manner, can someone explain the grain numbers in bullets. Example...a 9mm with 115 grain compare to one with a higher grain or lower grain. Is grain the gun powder? If the bullet are all the same size but different grains, is there fillers or something to make up for the difference? If you can give examples that will help alot.

farnorcal
08-11-2010, 11:21 PM
its a measurement of weight

Librarian
08-11-2010, 11:22 PM
Grains (http://en.wikipedia.org/wiki/Grain_%28unit%29) in that context denote the mass of the bullet - 1 grain = 64.79891 milligrams.

Holes, or 'dents' (e.g. 'hollow points') will lower the number of grains; different materials and proportions of metals may increase or decrease the mass of the bullet.

The amount of powder in the cartridge is also measured in grains, but that number usually is not specified unless one is reloading.

ke6guj
08-11-2010, 11:23 PM
"grains" is the weight of the bullet, measured in grains, http://en.wikipedia.org/wiki/Grain_(unit) .

assuming that the bullets are of the same type, such as a full-metal jacket bullet, a 115gr. 9mm bullet would be shorter than a 125gr. bullet or a 147gr. bullet.

Rule .308
08-11-2010, 11:23 PM
When they refer to grains in bullets they are units of weight. A 115 grain 9mm weighs half as much as a 230 grain 45. If you had a 230 grain 9mm, not that they make them, it would be the same diameter as the 115 but it would be twice as long. The gunpowder is also measure by weight and they use the same unit of measure, the grain. So if you look at your typical 45 acp it is going to use about 5 grains of powder to push a 230 grain bullet at about 900 fps. Clear as mud?

freonr22
08-11-2010, 11:24 PM
Speaking in a non-scientific manner, can someone explain the grain numbers in bullets. Example...a 9mm with 115 grain compare to one with a higher grain or lower grain. Is grain the gun powder? If the bullet are all the same size but different grains, is there fillers or something to make up for the difference? If you can give examples that will help alot.
7000 grains to a lb if that matters, or 15 +- grains per gram, or 437 grains per ounce, to put those in perspective. being a lil sarcastic, but really, those are about the conversion rates. I asked the same not too long ago. :)

iareConfusE
08-11-2010, 11:38 PM
Powder is usually also measured in grains when reloading, but the grain number you see on that box of commercial ammo is always going to refer to the weight of the bullet.

Guns R Tools
08-11-2010, 11:38 PM
If same amount of power then lower grain bullet will have higher velocity out of a barrel and also a lower recoil.

kAnJii
08-11-2010, 11:53 PM
If same amount of power then lower grain bullet will have higher velocity out of a barrel and also a lower recoil.

Please explain the performance part. A friend explained it this way. A stage coach being pulled by 3 horses compared to one being pulled by 5 horses. The 3 horses will go further and faster = lower grain , while the 5 horses will have more push and slower = higher grain. Is this correct?

SJgunguy24
08-12-2010, 12:40 AM
Please explain the performance part. A friend explained it this way. A stage coach being pulled by 3 horses compared to one being pulled by 5 horses. The 3 horses will go further and faster = lower grain , while the 5 horses will have more push and slower = higher grain. Is this correct?

Opposite, pick up a rock that weighs 8oz, Throw it as far as you can. Now pick up a 1lb rock and throw it.
Same push but double the weight. The heavy rock will not travel as far as the lighter rock if propelled by the same amount of force.

Guns R Tools
08-12-2010, 1:09 AM
Oops, I meant type powder not power.

ty423
08-12-2010, 1:45 AM
I believe on twist rate the weight of the bullet matters...especially for rifles.