copper bullet wound channel size ... caliber only?

sangreen

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Jun 17, 2014
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I read the match bullets for hunting and 223 TMK threads. They were brilliant, and changed the way I think about terminal performance. Unfortunately, I am restricted to non-lead bullets. Some follow-up questions and threads have come up on this topic, but as far as I can tell my specific question has not been addressed:

Is wound channel size for a copper mono purely a function of bullet caliber (edit: at fixed impact velocity)?

Example 1: Take a 150 gr bullet in both .308 and .284 cal (e.g. barnes TTSX). The .308 is wider, but the .284 is longer, so perhaps it could have similar frontal area upon opening (longer "petals")? Hold impact velocity constant.

Example 2: Sticking with TTSX, setting bc and velocity considerations aside to focus only on terminal performance, is there any difference in frontal area (expanded bullet) between say 120 gr and 150 gr .284 cal bullets? Hold impact velocity constant. Again here I am wondering if length/mass factors in to the expanded surface area and wounding potential of the bullet.

I ask this question because I think that it would be reasonably easy to test empirically, but I do not have the resources. I am aware that this could differ by manufacturer, and perhaps even within a line of bullets depending on design. Appreciate any insight.
 
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Jul 24, 2016
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The simple answer is no, wound channel is not purely a function of bullet caliber. As much as velocity is important for rifle bullets, velocity plays an even higher importance with the copper monos since they are so strong and the shape of the petals. The copper bullet penetrates deeper and holds shock producing velocity farther into the animal, while the shape of the expanded front is actually smaller, area-wise, than a lead bullet of similar expanded diameter. So it is this point-source of energy that creates the shock that creates the wound channel, much more so than a frangible bullet spreading out to wound mechanically.

In my experiences with the TTSX, I see small entrance and exit wounds and liquified lungs/heart area. It's always killed well for me but I do get some blood spoiled meat if impact velocities are upwards of ~2800 fps from a 130 gr .308" or ~2600 with a 250 gr .375". All in all I am satisfied with the TTSX but they aren't without faults like any other bullet.
 

hereinaz

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The newer all copper bullets from Cutting Edge, Patriot Valley, Hammr, etc are seeming to add performance over the Barnes. Technology and design is improving.

Wound channel is a function of direct tissue damage by permanent cavitation and the "shock" of temporary cavitation. Though more modern papers by military wound experts indicate the actual damage from the "shock" of temporary cavitation is much less than generally held belief. Tissue is fairly flexible, so there is less permanent damage surrounding the actual hole from temporary cavitation than we believe. Yes, it does blood shot meat from capillary, but that seems to be more akin to bruising per the article.

I think the jellied lungs is actually less jelly and more deflated. And, I say that as a person who believed in jellied lungs and thought I saw it. Who knows, so much is subjective.

Basically, put holes through both lungs and the animal will die. Nothing magic about it. Hit it in the ribs, and more animals seem to stand there, thunderstruck. But, hit them in flesh and the reflex is definitely to run like a cat or wolf bit them.

That's my educated guesswork.
 

prm

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A 338 cal TTSX impacting at high velocity makes a complete mess of internals. I’ve used 185s and 160s. Speed at impact seemingly makes the biggest difference I’ve seen. Difficult to quantify though. All ended up dead.
 

TomAZ

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Speed makes a huge difference. At 250+ yards, my 180 tsx from a .300 wsm get a complete pass through on a bull elk and don’t expand maybe a 1/3 over caliber diameter. The same bullet and load at 75 yards expands to almost 3/4” and comes to rest under the off side hide. YMMV


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sangreen

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Jun 17, 2014
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Thanks for the replies. I emailed some manufacturers about this question. The general consensus was that bigger bullets (either longer in the same caliber OR larger caliber) will result in more wounding potential. And, like was mentioned here, send them fast!
 
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Hard to tell in the pics. Golf ball sized exit. Through a shoulder blade. Impact velocity 3000fps with a 110gr .257 cal bullet. DRT.

Ive had much worse performance from 30cal copper bullets, but also much lower impact velocity.

IMO if using copper drop down to a lighter weight bullet and run it fast if you want bang flop performance! And shoot for the shoulder.
 

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