Firearm & Gun Forum - FireArmsTalk.com > Gear & Accessories > Ammunition & Reloading > Newb Question

Reply
 
LinkBack Thread Tools Display Modes
Old 02-21-2009, 05:09 PM   #1
Feedback Score: 0 reviews
 
Join Date: Nov 2008
Location: everywhere
Posts: 9,639
Liked 8 Times on 8 Posts

Default Newb Question

What is muzzle energy? I see it listed in foot lbs, but I haven't the foggiest about anything beyond that. Is there a simple definition?

__________________
Benning Boy is offline  
 
Reply With Quote

Join FirearmsTalk.com Today - It's Free!

Are you a firearms enthusiast? Then we hope you will join the community. You will gain access to post, create threads, private message, upload images, join groups and more.

Firearms Talk is owned and operated by fellow firearms enthusiasts. We strive to offer a non-commercial community to learn and share information.

Join FirearmsTalk.com Today! - Click Here


Old 02-21-2009, 06:40 PM   #2
Feedback Score: 0 reviews
 
hunter Joe's Avatar
 
Join Date: Feb 2008
Posts: 2,413
Liked 1 Times on 1 Posts

Default

Muzzle energy is the kinetic energy of a bullet as it is expelled from the muzzle of a firearm. It is often used as a rough indication of the destructive potential of a given firearm or load. The heavier the bullet and the faster it moves, the higher its muzzle energy and the more damage it will do. I got this info off ask.com Lots of confusing math there if you are interested. This will give you a basic idea.

__________________
hunter Joe is offline  
 
Reply With Quote
Old 02-21-2009, 11:33 PM   #3
Moderator
FTF_MODERATOR.png
Feedback Score: 0 reviews
 
c3shooter's Avatar
 
Join Date: Feb 2008
Location: Third bunker on the right,Central Virginia
Posts: 15,784
Liked 7615 Times on 3315 Posts
Likes Given: 1129

Default

Joe nailed it. It is distinguished from down range energy. Muzzle energy can be expressed in several different units of energy, but most common is ft lbs- derived by the formula, velocity squared times the bullet weight in grains divided by 450,240.

__________________
c3shooter is offline  
 
Reply With Quote
Old 02-22-2009, 12:08 AM   #4
Feedback Score: 0 reviews
 
canebrake's Avatar
 
Join Date: Jan 2009
Location: 150 miles NE of Sloppy Joe's Bar
Posts: 21,941
Liked 1406 Times on 805 Posts
Likes Given: 1290

Default

Quote:
Originally Posted by Benning Boy View Post
What is muzzle energy? I see it listed in foot lbs, but I haven't the foggiest about anything beyond that. Is there a simple definition?
Energy = 1/2mv^2, or energy equals one-half the mass of the bullet times the square of the velocity.

Thus, a 230 gr bullet that has a velocity of 945 ft/sec has an energy of (230 x 945 x 945) divided by 450380 = 456 ft-lbs.
450240 = A constant number in the formula which is two times the acceleration of gravity times the number of grains in a pound = 2*32.16*7000 = 450240.

Muzzle energy is not obtainable with instruments we use because to calculate energy we must measure the projectile's speed as the bullet passes through the screens of a chronograph. (~5 foot from the gun) This doesn't matter with respect to the velocities we shoot in small arms. The difference between "instrument" and "muzzle" velocities are insignificant.

Energy changes as the square of the velocity changes. If the 945 ft/sec bullet slows to 800 ft/sec, the energy drops from 456 ft-lbs to 327 ft-lbs. The velocity falls 15 percent. But the energy drops by 28 percent! Nearly double the loss.
__________________
http://i695.photobucket.com/albums/v...brake02jpg.jpg

http://i1060.photobucket.com/albums/...ps18cfbeae.jpg

Get her dirty, then clean her so she starts to respect you. When her trust is complete, she will serve you well for a lifetime!

"...if doves shot back, there wouldn't be a need for a bag limit."
- orangello
canebrake is offline  
 
Reply With Quote
Old 02-22-2009, 12:24 AM   #5
Feedback Score: 0 reviews
 
Join Date: Mar 2008
Location: I see you, and you will not know when I will strike
Posts: 24,301
Liked 3471 Times on 1606 Posts
Likes Given: 3590

Default

This just in, canebrake is a former engineer... in case you missed that part of his explanation above.

*high speed low level pass*

Thanks for that explanation cane, it's makes sense..... mostly.

JD

__________________
Dillinger is offline  
 
Reply With Quote
Reply

Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Firearms Forum Replies Last Post
Newb Question Dura-Ration AR-15 Discussion 2 05-24-2009 11:46 PM
Stupid Newb Question Jefe' AR-15 Discussion 3 11-10-2008 02:15 AM
Newb with Class III question mp5luvr NFA/Class 3 & FFL Discussion 3 04-13-2008 05:40 PM
newb to forum threaded ar-7 barrel question hkusp45 NFA/Class 3 & FFL Discussion 2 04-08-2008 04:35 PM



Newest Threads