Minimum Kinetic Energy

[Tumbleweed]

Ok, I know there are tons of opinions out there and plenty of real world experience with various bullets at long range. I have gotten comfortable with a number that I feel is adequate in regards to minimum kinetic energy on elk sized game. However, I am curious as to your real world experiences and what you feel is a minimum or 'enough' energy for a clean kill to see if I need to adjust that number. I know there are all kinds of variables such as bullet caliber, style, frontal area, and shot placement on the animal probably being the most critical. Fire away!

 

[J E Custom]

Ok, I know there are tons of opinions out there and plenty of real world experience with various bullets at long range. I have gotten comfortable with a number that I feel is adequate in regards to minimum kinetic energy on elk sized game. However, I am curious as to your real world experiences and what you feel is a minimum or 'enough' energy for a clean kill to see if I need to adjust that number. I know there are all kinds of variables such as bullet caliber, style, frontal area, and shot placement on the animal probably being the most critical. Fire away!

There is a chart with this information on it .

It is called the "Taylor knock out values" it is based on normal hits and has some margin for error.

It is a very good guide line.

J E CUSTOM

 

[FearNoWind]

Taylor Knock-Out Factor (TKOF)

http://www.n4lcd.com/calc/

https://www.google.com/search?q=tay...QTFkIDQCw&sqi=2&ved=0CEoQsAQ&biw=1231&bih=927

 

[Michael Eichele]

Bullet expansion and subsequent energy transfer and tissue damage is much more important than a mathematical equation for KE.

 

[davkrat]

I'm more concerned with impact velocity. I think you should keep your impacts at 2000 fps. Any reasonably constructed 130-180 grain bullet going 2000 fps put in the right spot should ruin any deer or elks day. Having to shoot copper bullets has made that point even more important.

 

[jrock]

Bullet expansion and subsequent energy transfer and tissue damage is much more important than a mathematical equation for KE.

I'm more concerned with impact velocity. I think you should keep your impacts at 2000 fps. Any reasonably constructed 130-180 grain bullet going 2000 fps put in the right spot should ruin any deer or elks day. Having to shoot copper bullets has made that point even more important.

I pay more attention to bullet design and minimum recommend velocity for them. You can back calculate the energy from that. More importantly than that I do like you are doing and research how far people have taken game with the load I'm considering using. Can't argue with results.

To put a number to your question though, I've heard 1000 lb*ft for deer and 1500 for elk. Compare a .243 95gr bullet with a 30-06 180 gr with similar bullet type and the 2000 fps only takes you to 450 yards with each gun. 30-06 has almost twice the energy and has 1500 ft*bls at 500 yards. Just to toss some numbers out there since people take animals at much farther distances with these guns.

 

[Tumbleweed]

1500 ft/lbs has been the number I've felt comfortable with based on experience and the good old rule of thumb that says twice the animals weight for kinetic energy. I use a RUM with a Berger 230 at a muzzle velocity of 3250fps. We are at sea level but that still puts that 1500ft/lbs of energy way out there. I am always willing to adjust my numbers some based on the experiences of others and that's what I'm looking for here

 

[elkaholic]

I believe there are so many other variables that affect killing, energy is overrated. While it is true that massive amounts of energy can cause trauma, through hydrostatic shock, that can kill quicker, most anmals are killed by blood loss and/or asphyxiation from blood in the lungs. To me, this means a bullet that destroys a lot of tissue, whether the energy is high or not. Quite often, this is more likely to occur with a bullet that HAS high energy because of the dynamics of velocity and mass playing a role in the tissue destruction. That said, if you have a bullet that expands, and especially one that fragments, you can cause a lot of tissue damage with fairly low energy. For this reason, I believe bullet construction that allows upset at low velocities can nullify the need for a lot of energy. I say this taking into account that this is a long range forum. If this were not true, archers could not kill much of anything and yet elephants have been taken with broadheads. IMO.........Rich

 

[jrsolocam]

1500 ft/lbs has been the number I've felt comfortable with based on experience and the good old rule of thumb that says twice the animals weight for kinetic energy. I use a RUM with a Berger 230 at a muzzle velocity of 3250fps. We are at sea level but that still puts that 1500ft/lbs of energy way out there. I am always willing to adjust my numbers some based on the experiences of others and that's what I'm looking for here

I'm having a hard time getting the 230's past 3,000 with H1000 and a 28" barrel, may I ask what your loads are?? Thanks.

 

[Tumbleweed]

I'm having a hard time getting the 230's past 3,000 with H1000 and a 28" barrel, may I ask what your loads are?? Thanks.

It's a full custom Remington 700 with a 32" broughton 5c running 101.5 grains of RL33, federal 215 gold medal primers, custom throating and a COAL of 3.830". Very mild load with no pressure signs on case.

 

[davkrat]

Here's some examples of 2000 fps energy values for various weights:

130 gr - 1155 ft/lbs. (Little light but I believe it meets most state's minimum muzzle energy requirement for elk.)
150 gr - 1332 ft/lbs.
168 gr - 1492 ft/lbs. (basically that magic 1500 ft/lbs)
180 gr - 1599 ft/lbs.
200 gr - 1776 ft/lbs.
230 gr - 2043 ft/lbs.

Many manufacturers claim that their bullets will expand at lower velocities but what they call expansion is not exactly anything to brag about. At 2000 fps even the sturdiest of bullets will tend to expand reasonably well. I like to have a fudge factor built in. Real life seems to present plenty of opportunities for Mr Murphy to come along and fudge things up.