Leupold BX-4 Rangefinding Binoculars

How important is it?

People can believe whatever they want on energy transfer but I’ve got a pile of phone scope videos, in fact I would venture to say nearly all, better than 95% of everything we’ve ever shot with a certain bullet has dropped where it stood. The rest went less than 100 yards and were mortally wounded. Prior to that I used bonded core or copper bullets (Barnes) and the norm was for the animal to run 20-200 yards then go down. If you were in California in 8’ tall brush that hadn’t burned in 100 years, full of ticks and rattlers, that can be a problem.

But I don’t think what you are witnessing is an energy transfer thing because at some point in flight the bullet you are shooting and a copper or bonded bullet will have the same energy or very close. Copper bullets and bonded have smaller wound channels than a fragile bullet coming uncorked in the vitals. I’ve witnessed the same thing with copper or bonded bullets that’s now why I shoot more fragile bullets. Things have just died quicker and covered less distance with more fragile bullets. That’s not saying copper or bonded bullets don’t kill they do just not as quick. I think you are seeing more fragmentation with your bullet choice now which makes a bigger wound channel than a bullet that holds together and that’s why you are seeing animals die quicker.
 
But I don’t think what you are witnessing is an energy transfer thing because at some point in flight the bullet you are shooting and a copper or bonded bullet will have the same energy or very close. Copper bullets and bonded have smaller wound channels than a fragile bullet coming uncorked in the vitals. I’ve witnessed the same thing with copper or bonded bullets that’s now why I shoot more fragile bullets. Things have just died quicker and covered less distance with more fragile bullets. That’s not saying copper or bonded bullets don’t kill they do just not as quick. I think you are seeing more fragmentation with your bullet choice now which makes a bigger wound channel than a bullet that holds together and that’s why you are seeing animals die quicker.
Bullet A and B have the same energy, bullet A passes thru the animal leaving a hole 1.5 times it’s diameter, then impacts a hillside 200 yards behind the animal. What amount of energy did it take to get the retained weight of that bullet to wherever it ended up? Bullet B enters the animal a couple inches then Displaces all its weight in multiple directions within the animal with little to nothing leaving, where did the energy go?
 
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Found a 8” twist 243 barrel I’m going to be putting on an action for my oldest to hunt with this year. Either going to try the 108 elite hunters or the 108 eldm depending on which shoots better
We pushed those bullets to the limit this season, I can pm you some videos, they did not let us down in the slightest. 6 lope and a few deer. I was tempted to shoot an elk with one they did so well. My new favorite for antelope hands down.
 
Bullet A and B have the same energy, bullet A passes thru the animal leaving a hole 1.5 times it’s diameter, then impacts a hillside 200 yards behind the animal. What amount of energy did it take to get the retained weight of that bullet to wherever it ended up? Bullet B enters the animal a couple inches then Displaces all its weight in multiple directions within the animal with little to nothing leaving, where did the energy go?

No argument from me that bullet b dumps all its energy in the animal. Just not convinced that energy is what causes the rapid kill. More of a velocity/fragmentation for me
 
Found a 8” twist 243 barrel I’m going to be putting on an action for my oldest to hunt with this year. Either going to try the 108 elite hunters or the 108 eldm depending on which shoots better
FWIW I observed my iffiest wound channel ever in a dead animal this year with a 108 elite hunter impacting an elk at ~ 2100 fps. I saw better results with an 88 ELD @ 1900 fps and way better results with a 103 ELD @ 2400 fps.

Probably a one off, as I know lots of others have had good results with the 108 EH, and I had them myself on another elk at ~ 2400 fps impact.

It’s my second eyebrow raising experience with a Berger at a lower impact velocity. I’m not swearing them off for game, but they’re taking a back seat for me for the time being.

To bring it back to the original subject of the thread, the 109 ELD is worth a look vs the 108 ELD for some essentially free BC. That’s what I used on the big buck Kurt posted.
 
No argument from me that bullet b dumps all its energy in the animal. Just not convinced that energy is what causes the rapid kill. More of a velocity/fragmentation for me

Agreed, I don’t think the energy itself is what’s actually killing the animal, likely massive internal tissue displacement, rapid rise and drop in blood pressure, blood loss, disruption in central nervous system, etc. but what’s causing it? The bullet that’s fragmenting (mass) at a velocity which = energy. Right or wrong I just think that’s the term people use to describe what’s an observable phenomenon.
 
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It was because of this forum I even knew what it was and why I thought it mattered. Hunting whitetail almost exclusively until 10 years ago, a long shot opportunity was 200 yards. I never considered trajectory, BC, muzzle velocity, terminal energy and I bought a whole lot of green and yellow boxes of 30.06 and .30-30 When i hunted out west, I had the opportunity to see animals at multiples of that and realized I wasn't practiced enough to consider shooting much beyond that. I bought a WSM and started looking at ammunition differently focusing on BC and trajectories. I still look at BC because I think it gives me a greater margin for error when ranging and shooting animals. My though process, btw open to the idea it may be faulty, is that with a better BC, the trajectory is flatter meaning a 15-25 yard difference matters less. That said, I still may not have shot far enough it mattered a great deal. I haven't shot anything over 450 with a 270WSM or 300 WSM.
 
Bc doesn’t matter if you’re using .243 Berger 95 grain vld target bullets for coyotes because even if you hit them, they are going to run like they arent hit and crawl down a hole.
 
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Yeah. Shitty set up for 23 years. mtmuley
I was just messing with you. The answer is it depends on your use case. If your hunting or shooting use case is short range where getting the bullet to target is going to be fairly easy no matter the projectile than obviously bc is not a big factor. Bullet performance for what I’m trying to achieve dictates. But once shooting conditions get more difficult such as wind and distance, bc helps get the bullet on target so bc is important because no amount of bullet construction/performance can overcome an off target shot. Even out of a 300 rum with a leupy😉
 
I've been killing animals for 39 years. And I mean, a lot of animals.

I didn't even know what the term meant until a couple years back when I ordered my first CDS dial and it asked me what the BC was for my bullet and I had no idea what that even was. I had to look it up. lol

So, no, its for sure not important for my needs and abilities.
 
Bc doesn’t matter if you’re using .243 Berger 95 grain vld target bullets for coyotes because even if you hit them, they are going to run like they arent hit and crawl down a hole.

That Berger is going 3”-4” before expansion starts on the hunting ones. The targets have an even thicker jacket so not sure when they’d start expanding. By that time you Almost all the way through a coyote so it’s basically an fmj on a broadside coyote . 90-95 grain ballistic tip, 90 grain eldx, 95 grain TMK would fix that issue for you. Did the same a few years ago.
 
Agreed, I don’t think the energy itself is what’s actually killing the animal, likely massive internal tissue displacement, rapid rise and drop in blood pressure, blood loss, disruption in central nervous system, etc. but what’s causing it? The bullet that’s fragmenting (mass) at a velocity which = energy. Right or wrong I just think that’s the term people use to describe what’s an observable phenomenon.
The energy transfer (via bullet destruction) is actually whats killing the animal - absolutely. It is not really up for debate, its physics. This is why fmjs aren't typically allowed (they wouldn't transfer energy)- although they will fragment above a certain threshold - typically north of 2500 fps.

No argument from me that bullet b dumps all its energy in the animal. Just not convinced that energy is what causes the rapid kill. More of a velocity/fragmentation for me

Absolutely it is. Velocity driven bullet fragmentation is energy transfer in action.

Think this is a good read for people interested in this topic.

 
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@mtmuley if BC doesn't matter, why don't you shoot a partition? I agree that it's not the issue that a lot of people make it out to be, but it also doesn't hurt. I agree that it's 'just clicks' when it comes to elevation but wind is where it can make a difference in my opinion. Care to post up your load data for your RUM so we can actually compare some real world numbers?
 
The energy transfer (via bullet destruction) is actually whats killing the animal - absolutely. It is not really up for debate, its physics. This is why fmjs arent typically allowed - although they will fragment above a certain threshold - typically north of 2500 fps.



Absolutely it is. Velocity driven bullet fragmentation is energy transfer in action.

Think this is a good read for people interested in this topic.


Maybe I’ve said it wrong but not saying there isn’t an energy transfer. I just feel people put too much thought into ftlbs of energy on target. Velocity and bullet construction are way more important in my opinion. How much energy does it take for a bullet to expand? I can tell you how much velocity it takes.
 
The energy transfer (via bullet destruction) is actually whats killing the animal - absolutely. It is not really up for debate, its physics.

Ok for the sake of debate, I get hit center of chest with a hollow point 45 point blank, bullet expands and transfers all its energy to my body, certainly I’m dead. Now I get hit exactly the same but I’m wearing a bullet proof vest, all of the energy is still transferred to my body, am I dead from the energy?
 
I think we can all agree it's a combination of things. All are important to some degree.

If you don't have enough speed or energy to get in to the boiler room and mess up some important organs, nothing matters!
 
Ok for the sake of debate, I get hit center of chest with a hollow point 45 point blank, bullet expands and transfers all its energy to my body, certainly I’m dead. Now I get hit exactly the same but I’m wearing a bullet proof vest, all of the energy is still transferred to my body, am I dead from the energy?

Or two cow elk shot side by side. One with a 200 grain accubond started at 3200 fps and one with a 140 grain Berger vld started at 2825fps. Both behind shoulder no major bones hit accubond caught on hide perfect mushroom on offside and Berger fragmentation against offside hide. Accubond cow ran 50 yards and tipped Berger cow went 10 yards maybe. Berger cow wound channel was quite a bit larger than the accubond cow. Accubond cow was hit with nearly double the energy of the Berger cow.
 
Ok for the sake of debate, I get hit center of chest with a hollow point 45 point blank, bullet expands and transfers all its energy to my body, certainly I’m dead. Now I get hit exactly the same but I’m wearing a bullet proof vest, all of the energy is still transferred to my body, am I dead from the energy?
Easy fix - don't shoot a deer/elk/bear/antelope/moose/mtn goat/bighorn sheep wearing a bullet proof vest. Coyotes are still fair game though, with our without vest.
 

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