What does grain mean?

Discussion in 'General Handgun Discussion' started by RonPaul2012, Jul 20, 2012.

  1. RonPaul2012

    RonPaul2012 New Member

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    I had no idea where to post this, so I posted it in handguns due to the fact when ordering .40 S&W ammo I always see different grain. I'm new to the technicalities of firearms and such, so I was wondering. What's the difference in grains? Right now, for example, I see 165, 170 and 180 grain for .40 S&W ammo. What's the difference?
     
  2. Vincine

    Vincine New Member

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    A 'Grain' is unit of weight. A 180 gr. bullet is 15 grains heavier than a 165 gr. bullet. 15 grains doesn't sound like much considering there's over 400 grains per ounce, but it translates into a bullet's momentum and impact forces. Given the same caliber and same load of powder, a heavier gr. bullet will be less affected by wind over distance, but have more of a trajectory drop than a lighter gr. bullet, which would be more affected by wind, but less affected by gravity.

    You'll need this for the quiz on Monday.
     

  3. rebelcowboy

    rebelcowboy New Member

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    That's a good question I'm not 100 percent certain my self but I think it has to deal with how much force the bullet will have when its fired I am new to all the technicalities of it also I just recently purchased a 1911 .45 and I would like to know the actual answer myself
     
  4. rebelcowboy

    rebelcowboy New Member

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    Thanks vincine I guess I was close
     
  5. RonPaul2012

    RonPaul2012 New Member

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    Oh okay, I was wondering if it had meant something to do with weight. I deal silver and I'm always dealing with grains, ounces and grams so I have a good understand of how much weight grains are but I didn't really expect it to be that simple when it comes to guns! Thanks a lot :)

    So you can't really practice with one grain in order to become a good marksmen with all grain, could you?
     
  6. rjd3282

    rjd3282 New Member

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    7000 grains = 1 lb.
     
  7. RonPaul2012

    RonPaul2012 New Member

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    Good God, a grain to pound conversion is insane... If you deal silver or other precious metals and you're familiar with Troy Ounces, just know that approximately 480 grains is equal to a Troy Ounce. Also, a Gram is about 15.5 Grains. There are 31.103 Grams in a Troy Ounce.
     
  8. Vincine

    Vincine New Member

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    If you expand the differences in bullet weights, it becomes easier to comprehend the principals involved:

    A paper clip is light, launched easily with a rubber band and quite fast across a room. It is also easily stopped and/or deflected. A mile long freight train being pulled by three locomotives is heavy, may only be moving at 5 mph, but should it jump the tracks, it may take a half mile or so to stop.
     
    Last edited: Jul 20, 2012
  9. Vincine

    Vincine New Member

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    As big as the difference is between shooting my .22 and my 9mm, and it’s a BIG difference, it’s nothing compared to the difference between shooting my 9mm and nothing at all. My .22 groups are getting tighter faster, but my 9mm groups are also getting tighter, albeit slower.

    It’s also easier for me to see the effects differences in position, hand grip, sighting, etc. are with my .22 than it is with my 9mm.

    Ultimately you do have to shoot with the gr. you wish to become good with, but practicing with a lighter caliber is far from wasted.
     
    Last edited: Jul 20, 2012
  10. string1946

    string1946 New Member

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    rjd is correct. The classic 38 wadcutter load is a 148 grain wadcutter bullet in front 2.8 grains of bulleye power.
     
  11. dan01

    dan01 New Member

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    I bought a bag of rice that was full of grains and it was heavy.
     
  12. MrWray

    MrWray New Member

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    They make a .45acp fragmentation round with a powdered rice core, its the 230 long grain FMJ
     
  13. The_Kid

    The_Kid New Member

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    No, the quiz starts now. ;)

    That is an incorrect statement.

    1.)Weight is not what cuts wind. Simple answer, better aerodynamics cuts wind better.
    This is a link to Hornady's ballistic calculator. (Use the advanced version.)
    I'm going to use a generic load as an example, which happens to be my 357 hunting load.
    I use a Hornady 180gr HP-XTP with a ballistic coefficient of .23, at a velocity of 1050. The sight height is .7, wind speed of 10, a 100 yard zero with a 200 yard max range; leave everything else as is.

    Note the wind drift at 200 yards, 9.5 inches. Now switch the bullet weight to 280grains and calculate. The wind drift is still 9.5 inches.
    Put the initial settings in and change the ballistic coefficient to .3 and calculate. The new drift is 7.5, 2 inches less.
    A bullet with the same ogive,[the curve of the nose,] that is heavier; is more aerodynamic than its lighter counterpart.


    2.) Drop is not subject to weight either. The reason the heavier bullet drops more, is because it is usually traveling slower; it takes longer to get to the target, whereas all bullets fall at 32 feet per second per second.

    Another example; put in the initial settings on the ballistic calculator again, then note the 200 yard drop, 37.1 inches. Now up the weight to 280grains and calculate. The drop is the same 37.1 inches.
    Now put in the initial settings and change the velocity to 850. The drop is 53.6

    Wind at a specific speed as well as gravity are constants that deal with time, so speed is a factor as well as aerodynamics in drift and drop, but weight in and of itself, has no effect.



    I might as well mention that, if all other conditions are equal, an increase in bullet weight increases energy.
    Again, use the initial calculator readings and note the energy, 317ft-lbs at 200 yards. Up the bullet weight to 280 and you have 494ft-lbs of energy; 177ft-lbs more than the lighter bullet.
     
    Last edited: Jul 21, 2012
  14. libwguns

    libwguns New Member

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    That would be the bullet for this gun, right? :D

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