Minimum foot pounds/velocity

[Young Gun 03]

Hey guys first ever post here. I was wondering, with say a 165gr projectile such as a Hornady sst out of a .308 what do u guys use as a threshold for foot-pounds or velocity? I was just gonna go with advertised velocity which is 1800fps but was wondering if someone used a different method of deciding your maximum range.

 

[19 Badger]

General numbers I hear get tossed around are 1800fps or 1200 ft. Lbs of energy, which ever comes first. More or less what I go by....

 

[codyadams]

Depends who you ask....general consensus seems to be:

1000 ft. lbs and/or minimum recommended velocity by manufacturer for bullet expansion, whichever comes first, for deer and antelope type game.

1500 ft. lbs and/or minimum recommended velocity by manufacturer for bullet expansion, whichever comes first, for elk and heavier built type game.

This will vary greatly by type of bullet used, and even atmospheric conditions. From my home at 6,500 ft elevation to my hunting grounds at 9,000+ ft elevation, my max ballistic effective range changes substantially.

 

[PredatorSlayer]

Hey guys first ever post here. I was wondering, with say a 165gr projectile such as a Hornady sst out of a .308 what do u guys use as a threshold for foot-pounds or velocity? I was just gonna go with advertised velocity which is 1800fps but was wondering if someone used a different method of deciding your maximum range.

I have killed elk cleanly with one shot below 1000 ftlbs of energy. I think what is important is that the bullet expands at whatever velocity you are anticipating at impact. Energy at impact is over rated imo.

 

[FEENIX]

Depends who you ask....general consensus seems to be:

1000 ft. lbs and/or minimum recommended velocity by manufacturer for bullet expansion, whichever comes first, for deer and antelope type game.

1500 ft. lbs and/or minimum recommended velocity by manufacturer for bullet expansion, whichever comes first, for elk and heavier built type game.

This will vary greatly by type of bullet used, and even atmospheric conditions. From my home at 6,500 ft elevation to my hunting grounds at 9,000+ ft elevation, my max ballistic effective range changes substantially.

I have the same unwritten rule at point of impact + the min recommended velocity (~1600 FPS) for bullet expansion.

 

[memtb]

Bullet placement is #1, combined at velocities that will provide good expansion makes a good combination. Even though expansion is "not" an absolute requirement.....heavy, hard cast, wide metplat, bullets are used on large, dangerous game very effectively at handgun velocities. Energy is way overrated! In summary: velocities that will assure adequate expansion, is a good "rule of thumb" for most hunting applications! memtb

 

[JASmith]

I have killed elk cleanly with one shot below 1000 ftlbs of energy. I think what is important is that the bullet expands at whatever velocity you are anticipating at impact. Energy at impact is over rated imo.

Consider a broad head arrow with a 1" + blade width. Big game has been and continues to be routinely taken with this size for at least 5,000 years. Energy of 750 gr arrow at 90-100 is almost trivial compared to most rifle bullets.

 

[memtb]

Anyone interested in getting some great information about bullet performance, should read this. It's long, and in places gets above my 3rd. grade math skills.....but is worth the read! Enjoy! memtb


http://rathcoombe.net/sci-tech/ballistics/wounding.html

 

[Plinker147]

The speed at which the bullet will perform is what I use to gauge max distance. Ft lbs is irrelevant if the bullet doesn't perform.

I use and would recommend you use the advertised performance velocity.

 

[Comancheria]

Not sure who came up with it--(I think it was someone famous, like Jack O'Connor, but it wasn't he)--but without regard to bullet weight or caliber, and ignoring the all-important aspect of bullet performance, (and all of that' ignoring a lot!) the old formula that I used to see kicking around oh, in '50s and '60s was as follows:

Deer/Pronghorn Size: Minimum = 900 ft lbs/Good = 1,200 ft lbs/Ideal = 1,500 ft lbs
Elk/Moose Size: Minimum = 1,500 ft lbs/Good = 2,000 ft lbs/Ideal = 2,500 ft lbs
Brown/Grizzly Bear: Minimum = 2,100 ft lbs/Good = 2,800 ft lbs/Ideal = 3,500 ft lbs

Whoever came up with that formula obviously used the idea that you picked a minimum for the size and disposition of the critter you were going to shoot, then added 1/3 of that for "Good" and 1/3 again for "Ideal". Pretty arbitrary, but it sure makes a nice, neat rule of thumb!

Best regards,

Russ

 

[Prairie]

Hey guys first ever post here. I was wondering, with say a 165gr projectile such as a Hornady sst out of a .308 what do u guys use as a threshold for foot-pounds or velocity? I was just gonna go with advertised velocity which is 1800fps but was wondering if someone used a different method of deciding your maximum range.

What has worked for me is, I'll decide on the components that I'll be trying out, work up a load using a ladder string, shoot it until I find what that particular rifle likes then push the envelope, load wise, watching for the group to start opening up and any pressure signs. When that happens, I'll back down to the best accuracy found and stick with that. (When doing the ladder test, I like to use .2 grain incriments until I find what I'm lookng for.) Seems to work for me! Just my $.02!

 

[FEENIX]

Here's one with Taylor's KO (https://en.wikipedia.org/wiki/Taylor_KO_Factor), using energy and momentum.

https://n4lcd.com/calc/

 

[PredatorSlayer]

Here's one with Taylor's KO (https://en.wikipedia.org/wiki/Taylor_KO_Factor), using energy and momentum.

https://n4lcd.com/calc/

Taylors KO was meant for dangerous game wasn't it?

 

[JASmith]

Here's a calculator that gives animal weight versus bullet weight and design -- as long as the velocity is within the manufacturer's performance window: http://shootersnotes.com/calculator/suggested-bullet-weight/