bullet energy limit

[WildRose]

I all ways like your post, understandable and to the point. I think what has made it so confusing for many is most gun writers spit out a number but do not state what game their are referring to. This makes some deer hunters thing they need a grizzly bear cartridge or an moose hunter think he is fine with a varmint/deer cartridge. Not that it can't be done, just not the best choses.

Keep in mind that a lot of "gun writers" really don't have a lot of field time behind their articles, they tend to give you target and ballistic data but very rarely are they guys who have put dozens of game animals on the ground every year for decades and kept good records on such things as terminal performance, point and angle of impact or all of those other variables that have to come together for a clean, quick, humane, one shot kill with minimal excess meat loss.

Honestly a lot of them are semi retired and writing their articles so that the companies they are reviewing will in essence sponsor them with freebies or very reduced prices on their products.

While I look to the guys with the education and experience on technical questions I tend to give much greater deference to the professionals with decades and hundreds of dead animals to their credit who don't sound like salesmen.

 

[skipglo]

This some thing I have found a bit amusing over the years and have not been able to get an answer to. So I thought I but on hear and see what every one on here thinks.

When I started reading hunting magazines in my early teens I was reading that a cartridge reached it's limit at 900 ft. lb. of energy. As time has gone by (30 + years) it has gone up. From 900 to 1000 to 1400 and now 1500. What has made the increase? I don't think the game animals have changed, and we do have better bullets.

Just wondering what every one thinks on this and share your thoughts. Do we just want more power?
This may all so be a good way to help some one pick a new rifle or a new hunter pick their first hunting cartridge.

What is equally important is the speed of sound. Once a bullet falls below 1160 ft/ sec it drops like a manhole cover, can wobble or even tumble...so perhaps a better value to judge viable distance of your shot plus energy for an effective kill...imho

 

[dhois]

I'm probably not following the question correctly as I am not clear on this from the OP: "a cartridge reached it's limit at 900 ft. lb. of energy."
I picked up Roy Chandler's gem, "Hunting Alaska" early on in my shooting years and adopted the preference for Momentum vs Velocity. Roy points out that Taylor's KO formula does not square velocity in the calculation, and while it can be considered an energy calculation, I'm not sure that's the best way to view KO. I do agree that modern (ie, available in 2019) bullet construction changes the KO recommendations quite a bit, but the answer to the forum posts asking How much Kenetic energy is needed for certain size game remains the same. My approach has been to call the bullet manufacturer and get their recommendation on minimum velocity at which they consider their round to be effective. I totally ignore KE.

 

[memtb]

dhois, I totally ignore any and all energy formulas/ extrapolations/ assumptions/ theory/ voodoo, ect. I simply use the largest caliber cartridge I can comfortably shoot, determine the range for acceptable expansion velocity, and base my maximum shot range on that value. The yardage determined, exceeds that at which I'm willing to shoot game! memtb

 

[BallisticsGuy]

People only talk about energy because science education is too poor in the USA to end up otherwise.

 

[birdiemc]

People only talk about energy because science education is too poor in the USA to end up otherwise.

What do you mean?

 

[FEENIX]

My PERSONAL criteria: whichever comes first.
1800fps minimum regardless of what animal
For pronghorn/deer sized game and down, 1000ft/lbs
For bear/elk sized game, 1500ft/lbs
I have never hunted anything bigger than elk like moose yet, but I think I might even go up to 2000ft/lbs in that case.

My unwritten rule is the same as yours. Of course, bullet choice and shot placement are critical but the "NUT" behind the trigger remains the biggest factor.

 

[BallisticsGuy]

What do you mean?

Kinda exactly this.

Energy is something specific and it's different to work or momentum or power which are also all specific things with actual meanings.

 

[lostinky]

A U.S. Navy 16" battleship round has 243,697,199 ft/lb of energy at the muzzle.

 

[birdiemc]

Kinda exactly this.

Energy is something specific and it's different to work or momentum or power which are also all specific things with actual meanings.

Gotcha. Very true

 

[entoptics]

People only talk about energy because science education is too poor in the USA to end up otherwise.

I disagree.

I talk about energy in projectiles all the time, and I certainly have a pretty extensive education in science... More relevantly, MANY accomplished hunters do the same.

Why? Because it is a good metric of 2 quantities required for creating wounds. Mass and velocity. In other words, it can summarize two variables in a relatively easy to compare number.

For example...

Generic "Hunting Ammo" A and B are both "expanding boat tail bullets", and both have about the same ballistic coefficient (or the drop printed on the box is roughly the same). Ammo A has 2000 ftlbs of energy at 350 yds and B has 1000 ftlbs at 350 yds. It's immediately obvious to me (and most reasonably educated hunters), that Ammo A is likely heavier (bigger) and suitable for elk and ammo B is likely smaller (lighter), and suitable for deer, and perhaps marginal for elk.

How do I know? Well, I know many folks have killed deer with a 243 Win (similar energy to B), but most anecdotes would indicate 243 is marginal for elk. Many people choose 30-06 or 7mm Mag for elk (similar to ammo A) and report great success.

In summary, I believe energy is a great synopsis of performance, when considered in tandem with bullet design. Sure it can be misleading, when comparing two radically different bullets like a 110 V-Max in a 300 WM vs a 130 Accubond in a 6.5 CM, but only the most uninformed would make that comparison.

 

[dfanonymous]

I disagree.

I talk about energy in projectiles all the time, and I certainly have a pretty extensive education in science... More relevantly, MANY accomplished hunters do the same.

Why? Because it is a good metric of 2 quantities required for creating wounds. Mass and velocity. In other words, it can summarize two variables in a relatively easy to compare number.

For example...

Generic "Hunting Ammo" A and B are both "expanding boat tail bullets", and both have about the same ballistic coefficient (or the drop printed on the box is roughly the same). Ammo A has 2000 ftlbs of energy at 350 yds and B has 1000 ftlbs at 350 yds. It's immediately obvious to me (and most reasonably educated hunters), that Ammo A is likely heavier (bigger) and suitable for elk and ammo B is likely smaller (lighter), and suitable for deer, and perhaps marginal for elk.

How do I know? Well, I know many folks have killed deer with a 243 Win (similar energy to B), but most anecdotes would indicate 243 is marginal for elk. Many people choose 30-06 or 7mm Mag for elk (similar to ammo A) and report great success.

In summary, I believe energy is a great synopsis of performance, when considered in tandem with bullet design. Sure it can be misleading, when comparing two radically different bullets like a 110 V-Max in a 300 WM vs a 130 Accubond in a 6.5 CM, but only the most uninformed would make that comparison.

I think he means that simply going by A) and B) examples as a way to measure a bullets terminal performance as by energy is not taking into consideration other things, or is misconstrued as energy. I've never seen a hunter consider momentum or a true scientifically take at power as a way to quantify a standard of lethality.

I only understand some of this through some reports related to doing R&D in the defense industry to be vague.

In my case I was apart of a revisit on the certain common handgun cartridges type thing, but none the less. It was a part of how some of the nerds were required to quantify lethality outside of just "energy" is my point. I've never see one of these type of studies on a long range bullet/cart combo. I'd be interested in reading if there was one but this is why I don't have anything to add to the OP, it can get overly involved and I don't have any numbers to share.

 

[entoptics]

I think he means that simply going by A) and B) examples as a way to measure a bullets terminal performance as by energy is not taking into consideration other things, or is misconstrued as energy.

I won't assume what BG means, but IMO, when "energy" is dismissed as "misunderstood, meaningless, etc" in these threads, it is just as ludicrous as dismissing bullet construction/design. Energy is one important variable to assess the ability to do work (tear tissue in this case). It's akin to saying "Bah! Horsepower is meaningless in a car race! It's speed that matters!"

I've never seen a hunter consider momentum or a true scientifically take at power as a way to quantify a standard of lethality ... I'd be interested in reading if there was one but this is why I don't have anything to add to the OP, it can get overly involved and I don't have any numbers to share.

I agree there isn't a great deal clarity in the testing that's been done. That's because it's a very difficult test. Lots of variables. That being said, there's lots of good information out there from science (application and experiment), and energy wouldn't come up so often if it wasn't an important metric.

To my car analogy. "Speed wins races, and it takes traction, power (work and time), and good driving to get speed".

IMO, for this topic, that's "Devastating wound channels drop animals quickly, and it takes bullet design, energy (speed and mass), and good shooting to get devastating wound channels".

Skill is beyond this discussion, but I think the other two are roughly of equal importance.

 

[Joefrazell]

I believe that most rifles consistent accuracy will run out much faster than it's effective energy/ fps range will. Usually caused by the guy behind the trigger and the awkward setup that we hunters alot of the time find ourselves in while trying to execute the shot. I mean energy is important but I'd much rather hit a deer, elk, moose ect. In the exact spot I'm trying to hit with half the energy or fps then a bad hit 2' back with twice the energy and velocity. Accuracy is King but it is still important to be sure that your cartridges performance is up to the task. Bullet selection being towards the top of that list.