Copper Ammo Recomendations

DagOtto

FNG
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Jun 19, 2024
Messages
98
I believe that the search for data to help to pick any bullet (lead or non-lead) is a valuable thing and that it should have some base-line metrics and standards to help make the data more defensible and to create consistent, reliable and accurate results.

There appear to be two ways to test for and analyze the performance of a bullet. The first is in lab testing by shooting bullets into gel. The second is field testing by actually shooting animals.

For the "lab testing" it is important to have a standardized protocol and methodology in place for obvious reasons. Because of that, I am of the opinion that the You-Tube testers shooting into clear gel should be taken as entertainment and not as reliable data. Hence my earlier post wishing out loud for an independent testing lab that could do this for real. As you will see below, I've found a few that exist and I intend to contact them to ask them how much it would cost to test a single bullet and/or a series of bullets and to discuss possible testing protocol.

For the lab testing there is a protocol already in place created by the FBI. Form talks about this a lot in his fantastically informative podcasts with the Exo Mountain Gear guys.

https://exomtngear.com/blogs/podcast/469

Here is an actual ballistic testing lab describing the FBI protocal for law enforcement bullet testing.


And here is a similar description from Hornady's law enforcement web site.


The standard testing protocol as described above was designed for testing bullets that were to be used in human conflict situations, so I don't think it is the ideal protocol for testing hunting. As I proposed in an early post, I'd suggest that every bullet be testing at varying impact velocities. (perhaps 3000, 2600, 2200, 1800, 1400fps) Furthermore, rather than testing the bullet through various "barriers" such as auto glass and drywall, I'd propose that the hunting bullet standard test includes a single simulant that represents hide and scapula. Some penetrative testing would need to be performed to come up with a good generic simulant, but I'm thinking of something like a single layer of astro turf spray-adhered to piece of 1/2" plywood be stuck to the front of the gel block to simulate hide and scapula in repeatable manner. It would be interesting to test a bullet on this and on just the plain gel block to see if there is any appreciable difference as maybe it doesn't make material difference and wouldn't need to be added.

As for the second way to collect data and test a bullet, this is the fun one. Field testing is being done and talked about on Rokslide every day! By it's nature it will not be as controlled as the lab testing would be. But if reliable data can be collected in big enough data sets I believe some trends and performance conclusions will become evident. Others with much more experience than me have said that over thousands of animals you can see a bullet's pros and cons pretty clearly. There is a study at Portland State that has just started which is trying to collect hunters terminal ballistic data and I can't wait to see their study results. They need lots of hunters to participate and enter their animal harvet terminal ballistic data. If you want to participate here is link to their data collection portal:


I have personally started wading through the massive number of necropsy and kill reports on Rokslide and have started a spreadsheet database linked to each post. I can tell you from starting that work that many of these posts don't offer enough data to be helpful.

To be helpful most of the following items need to be detailed in your posts:

Bullet and grains
Animal and Sex
Shot Distance
Impact Velocity
Time to Incapacition
Distance Traveled Before Collapse
Impact Location
Did it Exit?
Meat Loss Factor (1-5)
Were their follow-up shots
If so, where did they impact.

I will keep working on collecting this data from existing postts on RS and wil share it with you all when i get more on paper.

DO
 
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Lil-Rokslider
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Apr 2, 2021
Messages
126
Location
Kenai Peninsula, Alaska
Don't think what I'm doing is rocket science or requires this level of rigor but totally get you investing that time and hope you manage to get some clean data.

Im after a very specific niche
 

DagOtto

FNG
Joined
Jun 19, 2024
Messages
98
As for data that is already out there about bullet performance, here are few sources I've found.

Hornady's law enforcement site has lots of test data for different bullets. Here is .308 CX test data following FBI protocal.


The velocity of impact for all of these tests is pretty high at 2580-2730 which doesn't tell us how this bullet performs at lower velocities which is absolutely key for choosing a hunting bullet. BUT, in Hornady's latest podcast Seth specifically stated that for CX bullets their documented and tested MOB is 2000 fps but in general they would recommend "2100-2200" as the "ideal" MOV. It seems to me that running these same tests with impact velocities in the 2000-2200 range would be invaluable.

Without that data in hand, my take-away from this is that at 2000 fps impact velocity (on average) the CX bullet expands to Hornady's minimum performance goal of 1.5 x bullet caiber dia., but at that minimum expansion the bullet tends to kill more slowly and create less wounding than at the higher "ideal" velocity. For me personally then, my MOV for the Hornady CX bullet is 2150 fps.

Of special note to me is the comparison of the CX bullet performance between the 165 gr. CX in .308 caliber and the 70 gr. 5.56 caliber which is here:


When you compare the wound channel created by both you will find that the larger .308 bullet and the much smaller 5.56 bullet swing back and forth between which created the larger wound channel through various mediums. The only test in which the .308 was clearly a lot larger wounder than the 5.56 was through drywall. Otherwise the bullets traded back and forth in terms of which makes the biggest wound. This would appear to support the general recommendation that so many on Rokslide have adopted which is to shoot smaller calibers in order to increase shooter accuracy, target tracking and speed of follow-up shots.

As a side note, here is their test data for 155 gr ELD-M bullet in .308.


Although I find this data lacking because it does not show results at lower impact velocities, it does start to paint a picture that seems to reinforce general guidelines for bullet selection. It's a good start.

Finally (for now) here is a published data from Norma using their Ecostrike mono metal bullet in .308.
This clearly shows that as impact velocity drops, expansion drops dramatically. If we take Hornady's minimum performance standard of 1.5 times bullet diameter as an acceptable performance metric than the distance that this bullet could be called terminally affective would be roughly: 250yards when fired at 2800 fps mv, 350 yards when fired at 3000 fps mv and 450 yards when fired a 3200 fps mv. All of these estimates correspond with an impact velocity of around 2350.

Norma Expansion Data for Mono Copper.JPG
 
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Lil-Rokslider
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55gr CX's shot yesterday at 2235 Impact Velocity did not open at all, only tumbled. I've seen differering results for this round in other tests but in other calibers so my assumption so far is the CX offering in 223 is just not good. I'll do a 2400/2600 test at some point to verify where I do get opening but I didn't get a single open. All of them tumbled, veered left or right, and sometimes exited the gel.

I also tested the 50gr CX. I don't have chrono data on it yet but IIRC it didn't change. Will test again though later.

Very disappointed in this as I have a couple hundred rounds of it. For me it'll be target ammo at this point or maybe for brush/close range shooting only.
 

SDHNTR

WKR
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Aug 30, 2012
Messages
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55gr CX's shot yesterday at 2235 Impact Velocity did not open at all, only tumbled. I've seen differering results for this round in other tests but in other calibers so my assumption so far is the CX offering in 223 is just not good. I'll do a 2400/2600 test at some point to verify where I do get opening but I didn't get a single open. All of them tumbled, veered left or right, and sometimes exited the gel.

I also tested the 50gr CX. I don't have chrono data on it yet but IIRC it didn't change. Will test again though later.

Very disappointed in this as I have a couple hundred rounds of it. For me it'll be target ammo at this point or maybe for brush/close range shooting only.
The tumbling is likely due to a lack of stability, not velocity
 
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Lil-Rokslider
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The tumbling is likely due to a lack of stability, not velocity
Maybe but out of 2 different chamberings with a 1:8 and 1:7 twist I don't see where the stability issues would be introduced. It's typical for 55gr in this caliber to tumble when it doesn't expand. Weird how other bullets of similar length and grain are performing
 
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Lil-Rokslider
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After some research the clear gel I am using is known to slightly inhibit expansion and by extension, increases penetration. There isn't a great formula but for now I'm just going to use the handicap as a safety buffer and not judge any round as harshly until I can repeat in organic gel.

So the CXs are innocent until I do more testing but best I can tell it's likely still a high fps MOV (2000+ to expand). I was able to get them to expand today at 2550 (didn't try 2300-2400) and it did so beautifully with 6 even petals. Far more even than my tsx's but unfortunately takes to much speed to do it.

As seen on game in the past and to no surprise, the 110gr tac-tx in 300 blk expanded at 1500. I know they'll expand around 1300 but didn't push it out that far.

TSXs seemed to expand fine again today around 1800. Nothing amazing but in line with the testing done by brassfetcher.

Interestingly I tested some bonded bullets that penciled through or tumbled. The 70gr accubond was moving around 2200 at the muzzle and it broke the tip off and tumbled. 200 yds.

My block was pretty jacked up but pretty sure the FBIT3 (Trophy bonded bear claw, fbi load) penciled. However mushroomed perfectly at 25 yds.

Will shoot at some live game shortly and take notes
 

Thegman

WKR
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Nov 21, 2015
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Thanks for posting your results. May not be "perfect" testing, but comparing how the different bullets react is still interesting.

FWIW, I contacted Hornady about the 110 CX 30 Cal velocity window. He stated "They like to see impact from 2,400 down to 1,600 fps". Sounds like it might not expand as well as the 110 Tac-TX at lower velocities from what you've seen, but might be a better lower velocity choice in bigger 30 cals than some of the heavier CXs.

If the petals blow off, it still works like a Lehigh CC, and then down lower works as designed. I've killed deer with the 110 Tac-TX from a 308 loaded to about 2,700 - 2,800 fps. Lost petals, but killed just fine.
 
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Lil-Rokslider
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Best part of the TAC-TXs is when I say, saw expansion at 1400, I mean good expansion, not like "the tip kinda opened a little".
 

z987k

WKR
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Sep 9, 2020
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Finally (for now) here is a published data from Norma using their Ecostrike mono metal bullet in .308.
This clearly shows that as impact velocity drops, expansion drops dramatically. If we take Hornady's minimum performance standard of 1.5 times bullet diameter as an acceptable performance metric than the distance that this bullet could be called terminally affective would be roughly: 250yards when fired at 2800 fps mv, 350 yards when fired at 3000 fps mv and 450 yards when fired a 3200 fps mv. All of these estimates correspond with an impact velocity of around 2350.

View attachment 790380
So, for me, acceptable expansion is the 300wm at 250m. Not at 400m. 3006 at 150m, 308 at 100m.
 
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