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Terminal performance
@ 11:27 am (GMT) |
Scott StruifHornady posted an interesting video today that answers a question I’ve had about bullet design: . . . Are bullets in the same product line, such as ELD-X, designed so their terminal performance is proportional to their weight and diameter?In other words, say they designed a 6mm bullet to penetrate 1/4 inch and expand. You’d think the the 7.62 cal bullet would be designed to penetrate farther before expansion occurs. However, in the video, at 29:00, they state that they tweak jacket thickness, using ballistics gel, to get bullets of different diameters to expand at the same depth and create similar “wound channels.” Most hunters would assume that a 200 grain .30 cal bullet would be designed to penetrate at least twice as far as a 100 grain .243 bullet before expanding. The rapid expansion of the 100 grain bullet might be fine for a 150 lb. deer, but similar, rapid expansion on a 900 lb. animal is not what one would expect. This goes to show that one cannot draw any conclusion about the performance of a “line” of bullets from an isolated example of the performance of any given bullet from within that line. https://youtu.be/Q4jeYE3g43Q?si=KReY859TfhUSotli |
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@ 02:57 pm (GMT) |
Scott StruifRe: Terminal performanceIn the video, the mechanical engineer who designs the tooling for the presses stated that the 143 grain ELD-X was designed such that its terminal performance out of a 6.5 CM would be the same as that of a 103 grain ELD-X out of a 6 ARC. He said that by manipulating the jacket thickness of the 143 grain bullet, he was able to mimic the terminal performance of the 103 grain bullet, such that the “permanent wound cavity” and “penetration depth,” in ballistics gel, were the same.This is not good news for those planning to use the ELD-X on heavy game. The 143 grain bullet is 40% heavier than the 103 grain bullet. One would expect the heavier bullet to penetrate deeper, both before and after expanding. The 200 grain 30 cal. ELD-X is 40% heavier than the 143 grain version. From the ME’s statement, one can assume that it was designed to mimic the performance of the 143 grain version in gel. The ME confirms this when he talks about the 175 grain 7mm ELD-X later. At 42:15, he states that he would choose a 7mm 160 grain CX bullet for elk and moose, even though he was the ME on the team who created the 175 grain ELD-X. He states that, having seen, in real-time, not just pictures after the fact, how gel reacts to the ELD-X, he knows that the CX is going to penetrate deeper. He said the ELD-X is “dumping” too much energy on impact to penetrate. In his YouTube video, “7mm Practical, Testing the Hornady 180gr ELD-M,” Nathan provides convincing evidence that the even 180 grain 7mm ELD-M can smash through red deer shoulders at close to moderate ranges. There have also been reports on this forum of red deer shoulders being shattered and penetrated by 143 grain 6.5mm bullets. However, I’m not convinced that either a heavy ELD-X or ELD-M is the right choice for shoulder shots. I have an elk hunt coming up. The hunt area is a patchwork of private land and public land. I and my 2 hunting companions will be using 30-06 and 7mm RM guns. If we shoot an elk on public land and it runs, we will not be able to track and retrieve it on private land. The animal must be incapacitated sufficiently keep it from running. I have already decided that a shoulder shot is the highest percentage shot, providing a margin of error fore and aft. I don’t think a highly frangible ELD bullet is the right choice, even though I agree with Nathan generally that frangible bullets increase the odds of wider tissue damage, assuming sufficient penetration. I also disagree with Hornady’s choice of their CX bullet, based on Nathan’s research of all-copper bullets. My gut says a Scirocco, 150gr 7mm, or 180gr 30 cal., is the better choice. |
@ 06:28 am (GMT) |
Daniel SchindlerRe: Terminal performanceScott,While I can't provide any validity to what you stated, from a practical standpoint, I concur. A lot of common sense in your posts. You make a very sound argument and I appreciate your sharing both your study & your viewpoints. Well said Scott. All the best on your upcoming hunt.. Dan |
@ 07:12 am (GMT) |
Nathan FosterRe: Terminal performanceHi Scott, yes the frangible ELD-M is better for longer ranges or low muzzle velocities as opposed to tackling larger boned animals at close ranges / high speeds.If what the ME says is true, then the 143gr must have been altered recently - noting that the 6mm ARC was released in 2020 while the Creedmoor 143gr ELD-X was released in 2016. That or Hornady have cracked time travel. Do keep in mind that weight is always a factor. Weight x speed = kinetic energy. Besides jacket thickness, kinetic energy dictates bullet expansion. In other words, throw a bullet at a target and it won't expand, launch it from a rifle and it will. As the impact velocity changes, so does the rate of expansion. If the testing in gel is performed at certain speeds only (omitting truly long data), the results may be biased. Also, any test concerning gel is at the end of the day, relative only to the bullets ability to perform in gel, not hide, flesh and bone. I understand that Hornady are trying their best to increase business by providing information to hunters, but it may not be helpful to talk yourself round in circles until the viewer assumes that the ELD-X is no good for anything other than gophers and that your average Elk is closely related to the Tyrannosaurus Rex and is best dealt with using a vegan cooking recipe. In any case, you'll find plenty of info on bullet choices for your Elk hunt in the online knowledge base. Likely in the time it has taken me to write this, somebody somewhere has killed a Moose with a .30-06 loaded with factory Remington Core-lokt ammo. |
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@ 01:23 pm (GMT) |
Scott StruifRe: Terminal performanceHi Dan, and thanks. Pretty much everything I think I know, I learned from Nathan, or some member of this forum. I don’t have enough personal experience from which to draw any conclusions. However, the successes and failures I’ve had over the years have been consistent with Nathan’s research.Somewhere in the Knowledgebase, I noticed that Nathan found subtle differences in the performance of bullets of the same brand, type and caliber. I can’t remember the specific article. But I remember he found the performance of a lighter version of a bullet superior to a heavier version. Say, for example, a 150 grain version that worked better than the 180 grain version. That made me wonder if manufacturers manipulate the terminal performance of individual bullets within the same line by monkeying with things like jacket thickness. I knew that the 6 ARC was developed years after the 6.5 CM. The 103 grain ELD-X was probably developed for use in either the 243, or 6mm CM. Still, it was amusing to hear a Hornady engineer bragging about how the 143gr ELD-X performs the same as the 103gr version. What he meant was, their ELD-X is intended for use on small to medium, deer sized game. Same goes for the 150gr 7mm and 30 cal ELD-Xs. Hornady’s market for these bullets is the American whitetail deer hunter. When the ME stated, at 42:40 in the video, that he wants “a little more umph” than the 143gr ELD-X, the marketing guy tried to save the day with, “The 6.5 CM has recently taken a grizzly bear.” That was priceless! He could have said they make heavy ELD-X bullets, like the 30 cal 200gr ELD-X, for large game. But he didn’t. Which leads me to the conclusion that the 200gr version is designed to go “splat,” just like the 140gr. While it’s true Nathan has demonstrated the efficacy of heavy, frangible bullets, it’s clear to me that Hornady designed the ELD-X for the American whitetail deer hunter. In another video, Hornady stated that the ELD-X preceded the ELD-M. They said that, after buying their Doppler radar, and using it to develop the ELD-X, there was no enthusiasm to use it to improve their HPBT match bullet. Instead, they designed a new match bullet, the ELD-M, based on the ELD-X. It’s a happy accident that it’s a polymer tipped bullet, and thus suitable for long range hunting. |
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@ 03:59 am (GMT) |
Daniel SchindlerRe: Terminal performanceHi Scott.Reading your post above put a smile on my face. I too trust Nathan's experienced opinions on matters large and small. His books on rifles, cartridges, bullets, ballistics...a veritable chest of invaluable information, IMHO, worth heeding. My rifle / bullet / handloading collection reflects his preferences...for many good reasons. If I lived closer to him, after my 35th visit, he'd probably lock his door. A lot of my joy in shooting cmes from the rewards of learning. Hence my frequenting this site for its member's input. Like yours. Have a good week Scott. Dan |
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