Results 1 to 10 of 12
Thread: Foot Pounds of Energy
LinkBack URL
About LinkBacks-
11-17-2011, 02:19 PM #1Senior Member
- Join Date
- Aug 2011
- Location
- Willow Springs, North Carolina, United States
- Posts
- 1,490
- Glock Armorer?
- No
- Glocks Owned
- G21, G22, G19 gen 4, G30
- Rep Power
- 2
Foot Pounds of Energy
A friend of mine was asking me last night about reloading and the difference in energy with heavier bullets. He had a hard time understanding how a lighter bullet could produce more energy than a heavier one. Needless to say it turned into a math lesson on the coffee table. Once I showed him the calculations he had a better understanding of how kinetic energy comes into play.
I thought this would be useful information to those that might not be as familiar with reloading and ballistic data as others. You can use the equation below and plug in you own data to find the energy of the particular ammo you choose.
Foot pound of energy is calculated from Muzzle velocity squared multiplied by the bullet weight in grains divided by 450240. (4502420 is the only constant in this equation)
Example: 9mm Federal 124gr. Hydro Shock ammo
124 gr. w/ 1120 muzzle velocity
1120 x 1120 x 124 = 155,545,600 / 450240 = 345.47 foot pounds of energy.
Example: 9mm Federal 135gr. Hydro Shock ammo
135 gr. w/ 1060 muzzle velocity
1060 x 1060 x 135 = 151,686,000 / 450240 = 336.90 foot pounds of energy.
An interesting side note is that a heavier bullet will carry more energy at longer distances. In most cases at distances beyond 50 yards (impractical for most handguns) lighter weight projectiles will not produce the same kinetic energy of a heavier one.
At 25 yards, according to Federal’s velocity data the 135gr. round overtakes the lighter 124gr. bullet. As the caliber increases the yardage typically increases too.Don't retreat! Reload!!!
-
11-17-2011, 06:06 PM #2Super Moderator
- Join Date
- Jul 2010
- Location
- Sunshine State
- Posts
- 4,270
- Glock Armorer?
- Yes
- Glocks Owned
- Help... My Glocks have started multiplying...
- Rep Power
- 10
Good post!
That formula is the whole premise behind the military going with a small 5.56mm M16 round... But with lots of gun powder...
"While the anti-gunners seem very concerned about the "one life" that your firearm might take -- they are not very concerned about the lives it will save." Jon H. Gutmacher, Florida Firearms - Law, Use & Ownership.
-
11-17-2011, 06:52 PM #3Super Moderator
- Join Date
- Jul 2010
- Location
- Appalachian mountains
- Posts
- 2,382
- Glock Armorer?
- Yes
- Glocks Owned
- 17, 19(4), 20, 21, 21sf, 22(2), 23(3), 26(3), 27(2), 29, 30sf, 32, 34(2), 36(2)
- Rep Power
- 5
It didn't take me half that math to figure out I didn't want to get shot by any of them LOL. Seriously good post though
-
11-17-2011, 10:09 PM #4Senior Member
- Join Date
- Aug 2010
- Location
- Pacific NW
- Posts
- 885
- Glock Armorer?
- Yes- Oct '11
- Glocks Owned
- G17 Gen4, G19 OD, G20 SF
- Rep Power
- 2
Nice info. It's interesting to see how many caliber war threads are out there and not as many of these arguments take into account bullet velocity and total energy in the projectile. Big caliber bullet in a snubbie will have less kinetic energy than that .223 coming out of a rifle barrel at high speed.
-
11-18-2011, 06:54 AM #5Senior Member
- Join Date
- Jul 2010
- Location
- North Carolina
- Posts
- 1,247
- Glock Armorer?
- Yes
- Glocks Owned
- G17 L, G19 Gen4, G22, G26, G27, G20
- Rep Power
- 3
Good info, Tactworld. Thanks fo the post.
If you really want to fly, get out of the plane.
GLOCK Certified Armorer
G17L
G20, ATS Sights
G19 Gen 4, Trijicon Night Sights
G26, Glock Night Sights
G27
Ruger LCP
Mossberg 500A Persuader
Rock River AR 15
-
11-18-2011, 05:31 PM #6Senior Member
- Join Date
- Aug 2011
- Location
- Willow Springs, North Carolina, United States
- Posts
- 1,490
- Glock Armorer?
- No
- Glocks Owned
- G21, G22, G19 gen 4, G30
- Rep Power
- 2
You are exactly right. I was doing some figuring tonight playing around with the numbers. Getting shot with a 63 grain 5.56 nato round is roughly equivalent to getting hit with a 30 pound cinder block at just over 37mph. That's going to leave a mark. LOL
Originally Posted by __jb
Good post!
That formula is the whole premise behind the military going with a small 5.56mm M16 round... But with lots of gun powder...Don't retreat! Reload!!!
-
11-18-2011, 06:16 PM #7Senior Member
- Join Date
- Aug 2010
- Location
- Pacific NW
- Posts
- 885
- Glock Armorer?
- Yes- Oct '11
- Glocks Owned
- G17 Gen4, G19 OD, G20 SF
- Rep Power
- 2
I don't know which projectile would be worse. Messy either way :O Originally Posted by Tactworld45
-
11-19-2011, 06:54 AM #8Senior Member
- Join Date
- Oct 2011
- Location
- South of Texas
- Posts
- 1,070
- Glock Armorer?
- No
- Glocks Owned
- Several
- Rep Power
- 2
OUCH ! Originally Posted by Tactworld45
Thnkx for the math lesson, very good info, Sir !
Ot
... click Click BOOM ....
-
01-05-2012, 10:53 PM #9Senior Member
- Join Date
- Jan 2012
- Location
- Norman, OK
- Posts
- 275
- Glock Armorer?
- Yes
- Glocks Owned
- 19, 22, 27
- Rep Power
- 1
All the above is correct but please also remember two other important numbers.
Sectional Density
Ballistic Coefficient
Both play importance in energy and flight
-
01-06-2012, 02:32 AM #10Super Moderator
- Join Date
- Jul 2010
- Location
- Sunshine State
- Posts
- 4,270
- Glock Armorer?
- Yes
- Glocks Owned
- Help... My Glocks have started multiplying...
- Rep Power
- 10
Correct... Lots of factors determine the overall effectiveness of each individual round... Some of them are open to interpretation, otherwise we'd all be shooting the same exact ammunition... Here are a couple of Wiki pages for "extra credit" reading if anyone is interested... Originally Posted by OklahomaSafeShooting
Sectional density - Wikipedia, the free encyclopedia
Ballistic coefficient - Wikipedia, the free encyclopedia"While the anti-gunners seem very concerned about the "one life" that your firearm might take -- they are not very concerned about the lives it will save." Jon H. Gutmacher, Florida Firearms - Law, Use & Ownership.
Reply With Quote
