6.5's for elk

[Newtosavage]

So, I'm still trying to learn here so forgive my ignorance...

But if impact velocity and bullet construction are all that matters, they why does anyone shoot a .30 cal (or larger) anymore?

I mean, why put up with the recoil and extra weight of a .300 Win Mag if a .243 can achieve the same impact velocity with the same bullet construction?

 

[Formidilosus]

So, I'm still trying to learn here so forgive my ignorance...

But if impact velocity and bullet construction are all that matters, they why does anyone shoot a .30 cal (or larger) anymore?

I mean, why put up with the recoil and extra weight of a .300 Win Mag if a .243 can achieve the same impact velocity with the same bullet construction?

Depends on the bullet type. If using monolithics (say 180gr 30cal, 85gr 243), the actual wound channels can and will look very similar, with the 180gr penetrating farther. If you had two deer shot in exactly the same location with both, you would be hard pressed to know which was which a lot of the times.

However, if using fragmenting bullets like Berger or Hornady ELD-M’s- there is a noticeable difference. The heavier bullet can either give a wider wound at the same penetration depth, or penetrate deeper at the same width.


Normal bonded/controlled expansion bullets fall in the middle.

 

[Newtosavage]

Geez, you just like pulling the tiger's tail?
I thought this got beat to death and then some in the 243 thread?

Not pulling any tails, just trying to understand what seems to be contradictory advice and behavior. Gotta be something I'm missing here.

 

[ericF]

Not pulling any tails, just trying to understand what seems to be contradictory advice and behavior. Gotta be something I'm missing here.

Wind drift is a big one. 180gr TTSX out of a 300 win mag will give you 36" of wind drift with a 20mph horizontal wind at 500 yards. A 80gr TTSX out of a 243 will give you 51.1" of wind drift in the same condition. In addition, the retained velocity of the 80gr TTSX would be 1842 fps with a retained energy of 602 ft pounds, whereas the 180 gr TTSX will still be 1985 fps with a retained energy of 1575 ft pounds. That is a huge difference in retained energy that you get from the larger round.

 

[Newtosavage]

That is a huge difference in retained energy that you get from the larger round.

That's just it though - folks are making the argument that it's not energy but velocity and bullet construction that matters.

So, given the same bullet construction and same velocity, why are people choosing magnums vs. 243's and 6.5 CM? Is it so they can achieve those velocities at further range? Is that the only reason?

Put another way, aside from energy what is the difference between a 6mm Accubond and .338 Accubond traveling the same speed if it's not energy?

 

[30338]

Quite a bit of felt recoil is a big difference. My poor daughter will be chasing elk this fall with a 6.5 shooting 140 vld bullets at 2700 fps. Hope it works.

 

[prm]

Wind drift is a big one. 180gr TTSX out of a 300 win mag will give you 36" of wind drift with a 20mph horizontal wind at 500 yards. A 80gr TTSX out of a 243 will give you 51.1" of wind drift in the same condition. In addition, the retained velocity of the 80gr TTSX would be 1842 fps with a retained energy of 602 ft pounds, whereas the 180 gr TTSX will still be 1985 fps with a retained energy of 1575 ft pounds. That is a huge difference in retained energy that you get from the larger round.

A 147 ELD-M out of a 6.5 Creedmoor at 2740 at 9k’ (the lowest point where I hunt elk) will have 19.6” of windage with a 20 mph crosswind at 500 yds. It will arrive at 2260FPS and 1667ft/lbs of KE. (Sea level would be 26” windage, 2121fps and 1469ft/lbs). Some of the bigger 6.5s are that much better. And that’s the magic of those looong, pointy 6.5 bullets. Of course you could choose much better long range bullets for the win mag. The point is, bullets matter at longer ranges, and ones that minimize the guesswork of wind help to effectively punch holes in the vitals.

 

[Newtosavage]

So then what IS the advantage of the magnums, or even the '06 for that matter?

 

[prm]

You do reach a point where more ooomph is better. It just doesn’t happen at the ranges I intend to shoot. I don’t shoot enough at long range to feel confident, so I don’t. To be more specific, I don’t find myself hunting areas where I’m in a stable enough position to feel confident at longer range shots. As a bow hunter, who now also rifle hunts, I don’t feel at all limited by staying under, well under, 500 yds. My last bull elk was at closer to 40yds.
The fatter the bullet, the longer the ranges, the more powder you’ll need to get the bullet out to those longer ranges at a velocity where they will reliably open. Others here can speak to those attributes much better than I though.

 

[cs68]

Close friend and hunting buddy drew a cow tag here in Michigan, and brought his rpr in 6.5cm (precision hunter 143 eld-x). He got it done within 200yd iirc, said he thought he missed. Said she didn't even flinch, just tipped over 15 seconds after a follow up shot.
His thoughts on the hunt were, "it obviously can take elk, but I should've brought my 7 mag"

 

[mt100gr.]

So you’re not going to go into basics on how you use KE to determine bullet selection of construction and such? Than how is that supposed to help the rest of us. Just believe what it says on the side of the box?

Sorry I just thought a dumbed down version of how you rank bullet construction in conjunction to velocity and KE leads you to select this or that cartridge or bullet for this or that critter? Or is it all too advanced you can’t possibly give us a readers digest example of how you figure this and when certain variables are more important than others?

I know myself would benefit certainly and many other readers would as well to glean from your expertise.

Please and thanks in advance to trying to dumb it down in an example for us.

We might just have to stick with using those minimum impact velocity thresholds....seems to work OK and apparently it's more user friendly to know that bullet performance will suffer once your VELOCITY dips below a certain level. But I'm no physicist.

 

[JigStick]

Kinetic Energy, bullet geometry, bullet construction, and anatomy cause wound channels. Velocity is only worth talking about in the context of one specific bullet - which means you are actually talking about KE. If you are comparing multiple calibers and/or multiple bullet lines/grains/etc., velocity means absolutely nothing. There is zero room for opinion in the science.

If you are trying to compare different bullets and/or different calibers, you need to look at KE, bullet geometry, & bullet construction to make any sort of useful comparison.

The statement was made that a 6.5mm cartridge is outperforming a 300wsm. Which is total bullshit. I have both calibers. And have compared shooting heavy bullets out of each.

My 6.5 Creedmore shooting a 140 Berger VLD at 2900 doesn't even come close to the performance of my 300wsm shooting a 210g Berger VLD at 2850. Bullet drop, wind drift, energy delivery, blah blah blah.

Same bullet, similar velocity, the 30cal has a lot more mass to delivery energy. So If someone is getting magical performance out of a 6.5 Creed, 260Rem, even a 6.5 SAUM that can outperform a short mag Id love to see the chrono data and ballistic tables to back it up.

 

[tyeager2964]

I am not sure I want to jump in here but there is one argument for fragmenting bullets that I havent ever recalled reading here directly.

Broz, Ryan and others have indirectly touched on it but I can't recall anyone specifically saying that the surface area of the bullet matters.

If a fragmenting bullet is ment to "explode" aka Berger then surface area has to matter as a larger area has more fragments.

This also explains why a TMK is so destructive.

In my mind it is easy to see why using a large grenade vs a small grenade makes a difference. Greateer surface area equals more fragments equals greater tissue destruction.

You can then argue all the math for velocity KE material strain and bullet construction but all things being equal the larger grenade the more fragments the more damage

 

[Ndbowhunter]

The statement was made that a 6.5mm cartridge is outperforming a 300wsm. Which is total bullshit. I have both calibers. And have compared shooting heavy bullets out of each.

My 6.5 Creedmore shooting a 140 Berger VLD at 2900 doesn't even come close to the performance of my 300wsm shooting a 210g Berger VLD at 2850. Bullet drop, wind drift, energy delivery, blah blah blah.

Same bullet, similar velocity, the 30cal has a lot more mass to delivery energy. So If someone is getting magical performance out of a 6.5 Creed, 260Rem, even a 6.5 SAUM that can outperform a short mag Id love to see the chrono data and ballistic tables to back it up.

.7 at 2850 (147gr eld and reloder 26) beats .63 at 2850 at all ranges pertaining to drift, drop, and velocity

Not sure why you’d even pick that argument.

 

[JigStick]

.7 at 2850 (147gr eld and reloder 26) beats .63 at 2850 at all ranges pertaining to drift, drop, and velocity

Not sure why you’d even pick that argument.

You’re joking right? I have a 1400yd Range in my backyard and have slung 1000s of rounds at steel back there. The 30cal pills buck the wind way better.

You can’t compare BC and terminal performance against each other between dissimilar calibers. It doesn’t work that way. Yeah that 147 will fly better than it’s equivalent 130. Given it’s the same cartridge.

And I’ll reiterate this again. A 210g 30cal bullet is going to transfer more energy into the game animal at any range compared to the same bullet weighing 147g. Unless Brian Litz over at Berger is wrong lol

 

[204guy]

@406Smith does the bullet stress impact formula take into consideration that bullet manufacturers often increase jacket thickness as caliber increases within the same bullet line? And how does this affect the relationship of expansion energy required of smaller lighter jacketed bullets. And heavier larger cal bullets with thicker jackets? Probably not explaining very well, basically given the 1300fps impact velocity of the ablr line, would thicker jackets as cal increases make bullet upset more similar? Just trying to learn also.

Sent from my SM-G935V using Tapatalk

 

[Ndbowhunter]

You’re joking right? I have a 1400yd Range in my backyard and have slung 1000s of rounds at steel back there. The 30cal pills buck the wind way

Nope, just curious how a .7 bc bullet moves more in the wind then a .63bc bullet given the same launch speed.

I’ve never shot much past 250 yards, but the online ballistic calculator i’ve Ever played with say a higher bc at any given launch speed will always drift less in the same wind speed and direction

 

[Formidilosus]

Ha! No nerves struck here fella. I must just be bad at conveying tone.

I don’t have any easy button. For me to tell you the exact stress needed to strain any given bullet to yield or rupture, I would need to set-up a finite element analysis and calc out by hand (that’s the only way a non-expert like me knows how). I’ve never needed to know the gnats-ass answer so I haven’t wasted my time.....plus it would really take away from my online posting time .

So in other words KE doesn’t tell me f-all about how much damage a particular bullet will do in tissue, nor how deep it will penetrate? I said in the other thread that engineers are always trying to turn terminal al ballistics into a “math nerd” thing. This is true. Otherwise you wouldn’t have wanted to send your “college textbooks” to reference tissue damage of bullets.





Knowing the KE of a particular bullet will tell one NOTHING about how much tissue damage will occur, how wide the wound will be, or how deep it will penetrate. Nothing. It is a useless metric for practical knowledge of terminal ballistics. Bullets are designed to expand/fragment at a certain velocity. That IS useful knowledge to a hunter. Berger VLD’s will have fragmentation down to around 1,900fps without hitting major bones. That is across nearly all calibers. There is NO math equation that will tell you how much damage they will do in tissue at 1,900fps impact. To know that you must shoot tissue, or properly calibrated tissue simulate (ie.- 10%ballistic gel) repeatedly. Then you measure the impact velocity, neck length, depth to temporary stretch cavity, max temporary stretch cavity, permanent crush cavity, and total penetration depth. Done correctly this gives you a high correlation to what that bullet at that speed will do in tissue.
Below 2,000’ish FPS impact the temporary stretch cavity has relatively minor permanent wounding unless fragmentation occurs. It’s “ish” because it is somewhere around 2,000fps, however large differences in projectile diameter can make a difference. Note- large differences. The difference between .224 and .308 will not generally show below 2,000fps impact.



Bullets kill by damaging tissue. That tissue is damaged by being torn, pulped, penetrated, stretched, or bruised. It must be measured to know what and how it will damage tissue. No legitimate terminal ballistics facility even calculates kinetic energy, because it gives to no useful information. Two identical weighted, and sized bullets will have identical KE numbers yet completely different results in tissue. Likewise, bullets can have 2,000 ft-lbs energy differences, yet behave in tissue near identically.


The path to knowing how your bullet will kill, is to shoot it into tissue simulate (or live tissue if you have dozens to hundreds of specimens), find out the maximum and minimum impact velocity for upset, and measure the wound path. That’s it. There is no way to do it other than that.

 

[Formidilosus]

You’re joking right? I have a 1400yd Range in my backyard and have slung 1000s of rounds at steel back there. The 30cal pills buck the wind way better.

You can’t compare BC and terminal performance against each other between dissimilar calibers. It doesn’t work that way. Yeah that 147 will fly better than it’s equivalent 130. Given it’s the same cartridge.

And I’ll reiterate this again. A 210g 30cal bullet is going to transfer more energy into the game animal at any range compared to the same bullet weighing 147g. Unless Brian Litz over at Berger is wrong lol

Umm... what?


I would like to see the magical place on earth that a higher BC bullet drifts more than a lower BC when launched at identical velocities. I only have acces to a 1,500 yard Doppler radar, but BC is BC. The higher BC bullet will always drift less than lower BC regardless of caliber if starting velocity is the same.

To your point of “energy”. It is not a wounding mechanism. It may transfer more energy to an animal, but that energy doesn’t tell you anything about what wound will be created. It is quite possible for a “147gr” bullet to create more tissue damage than a “210gr” bullet. It can, and in fact does happen.

 

[Ndbowhunter]

You know there is a difference between velocity and speed yeah?

However in normal language we use the term interchangeably.


Also you cannot have “velocity” or “speed” without mass.

Unless we’re talking frickin lazer beams
It that case you should show kills with lasers.