bullet expansion test results

[firstcoueswas80]

Could I send you some 180 grain 7 millimeter hybrid and Lapua scenars?

 

[RockyMtnMT]

Here is a couple of pics of recovered 270cal 133g Sledge Hammer from a black wildebeest 200y impact. With the muzzle vel of 3400fps that would make impact at roughly 2900fps. Dave did not say what retained weight is but should be about 105g or more. These pics are exactly as we get in our testing.







Steve

 

[yorke-1]

Could I send you some 180 grain 7 millimeter hybrid and Lapua scenars?

Sure! I''ll send you a PM with my address.

Here is a couple of pics of recovered 270cal 133g Sledge Hammer from a black wildebeest 200y impact. With the muzzle vel of 3400fps that would make impact at roughly 2900fps. Dave did not say what retained weight is but should be about 105g or more. These pics are exactly as we get in our testing.



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Steve

I love the fact that they're moving fast enough to actually get expansion from a solid copper bullet!

 

[Predator 22]

Yorke-1 do you have anything that will stabilize the 195 bergers?

 

[Mitch Rapp]

After reading through this thread, not much for me to add, but definitely wanted to say thanks for the work put into it. Very well done.

 

[smithjasona1978]

Bump

 

[yorke-1]

I'm short a couple employees at work so I'm back to working six days a week until I can get a few more guys hired. Because of that I've bee pretty short on time lately, but I hope to get out this weekend to do one last round of testing. I'm down to just a couple bullets left other than some odd varmint bullets. I'll work on getting all the data I've collected sorted out and organized when I'm done. I think I'll have tested somewhere around 50-55 bullets by the time I'm done.

Andrew

 

[smithjasona1978]

Great. Thanks for the thread.

 

[yorke-1]

I've been pretty busy for the last few weeks so this project has been kicked to the back burner for a while. As in past tests, impacts were at 100 yards unless otherwise noted into the wet leather. 270 bullets were fired from the 270 AR, 284s from the 284 Win Striker, 30 calibers from the Ruger 77 Tang safety 300 Win Mag, 358s from the custom 35 Whelen, and 375s from the Ruger Hawkeye Alaskan 375 Ruger.

270 AR
- 117gr Hammer Hunter
- Muzzle velocity 2732 fps

Impact velocity is approximately 2455 fps with a retained weight of 79.8 for just the bullet shank and a combined weight of 109.8 including the recovered petals. Only one bullet was fired into the leather due to a limited number of loaded rounds on hand when I went testing. Performance was typical of all the other Hammer bullets I've tested and this particular bullet is my new hunting bullet in this gun. I'll start a new thread to go over that.


284 Win
- 155 Cutting Edge MTH
- Muzzle velocity 2323 fps

Impact velocity is approximately 2130 fps with retained weights of 155gr each. I was pretty confident that this bullet wasn't going to stabilize from my 9.5" twist barrel and appears that is what happened. The bullets didn't expand and tumbled shortly after impact.


- 160 Sierra Tipped MK
- Muzzle velocity 2332 fps

Impact velocity is approximately 2190 fps with retained weights of 139.5gr and 54.2gr. One bullet completely fragmented and only a few small pieces were recovered; I don't have any explanation for the performance of that particular bullet.


300 Win Mag
- 150 Dead Blow Hammer
- Muzzle velocity 1805 fps

Impact velocity was approximately 1640 fps with retained weights of 150gr for both samples. This bullet was tested at the extreme low end of velocity just to see how they would perform since moderate to high velocity performance of the Hammers has proven to be very consistent. To test these bullets, they were each fired into a 1 gallon water jug placed in front of the leather to help initiate low velocity impact. It appears that the impact velocity was too low (recommended velocity is 1800 fps) to effectively initiate expansion even with the 1 gallon water jug to help. I'll try these again within the recommended velocity window as well.


- 208 ELD-M
- Muzzle velocity 2130 fps

Impact velocity is approximately 2005 fps with retained weights of 182.4gr and 187.5gr. Performance of the Hornady ELD line of bullets has been very predictable in every test and this time is no different.



35 Whelen
- 225 Sierra Game King
- Muzzle velocity 2623 fps

Impact velocity is approximately 2386 fps with retained weights of 208.9 and 213.9gr. This is my practice load in the 35 Whelen which is why it's a higher muzzle velocity relative to other bullets tested.


- 225 TTSX
- Muzzle velocity 2757 fps

Impact velocity is approximately 2500 fps with retained weights of 224.6gr and 225.0gr. This is my hunting load in this particular gun and I didn't have any bullets available to load reduced velocity test loads.



375 Ruger
- 300gr Sierra Game King
- Muzzle velocity 1940 fps

Impact velocity is approximately 1775 fps with retained weights of 295.4gr and 291.7gr. This is roughly the same impact velocity that at full power load from either a 375 H&H or 375 Ruger would have at 475 yards. The bullet didn't expand as well as I expected considering the large exposed lead nose.


- 350gr Sierra MK
- Muzzle velocity 1780fps

Impact velocity is approximately 1690 fps with a retained weight of 350gr. The muzzle velocity ended up being much lower than I expected, but I was confident that this bullet would be under stabilized anyways. As expected, the bullet was unstable on impact and tumbled so only one was fired.


This is likely the last round of tests that I'll get done. The supply of donated bullets has slowed down considerably and I'm running out of worthwhile bullets to test from my personal stash. I'll keep testing when I get enough samples to be worth setting up the leather or if I get a bullet that I'm just really interested in testing. Here's a quick run down of all the samples I've tested. I'm pretty sure I've included write ups on all of them, but if anybody sees one pictured that you don't remember seeing the data on, just let me know and I'll dig it up

6mm


6.5mm


270


7mm


308


338


358


375


458


475


And a couple of the whole line up.

 

[yorke-1]

I just realized that I didn't include the 6.5mm 130gr Accubond in the bullet line up! I knew I'd forget at least one!

 

[codyadams]

I'll go through my bullet supply, and see if I have any decent ones you haven't tested to start another set of donated bullets.

Your hard work is much appreciated, and has also shown something that alot of people probably don't consider when it comes to bullet expansion, and that is bullet stability.

About what threshold have you found to be necessary for proper expansion as far as stability goes? Is it the standard 1.5 or does it seem that a higher stability is necessary? Thanks again for all your hard work

 

[RockyMtnMT]

I'll go through my bullet supply, and see if I have any decent ones you haven't tested to start another set of donated bullets.

Your hard work is much appreciated, and has also shown something that alot of people probably don't consider when it comes to bullet expansion, and that is bullet stability.

About what threshold have you found to be necessary for proper expansion as far as stability goes? Is it the standard 1.5 or does it seem that a higher stability is necessary? Thanks again for all your hard work

Not stepping in front of Yorke here, I am sure he will chime in as well.

In our testing I have come to (or coming to) the conclusion the 1.5sg should be considered a min number for terminal performance. The closer the number gets to 2sg or higher the better the bullets perform. Particularly at low vel impacts.

My theory on this is the rotational vel of the bullets stays nearly the same through out the flight of the bullet and keeps it oriented point forward. The rotation is what keeps the heavier base from passing the nose. The heavier base is always trying to get in front. Once the bullet makes contact the rotational vel begins to degrade rapidly. So as the bullet moves through the media the sg decreases and the heavier base is trying to pass or tumble. At the moment the sg below 1.5 the tumble begins taking the force off the tip of the bullet and stopping the proper deformation.

The higher the sg gets the farther we see bullets penetrate before they lose orientation. I am coming to the mindset that my hunting bullet choice will include the stability factor and weigh out the loss in effective range due to lighter bullets lower bc, and better terminal performance on impact. I am fairly certain that I will be changing my hunting set up from 285g Hammer Hunters to 213g Hammer Hunters in my 338 Lap imp. I gain a lot of vel with the 213g and the 285g can't catch up until 1000y for wind and further yet in drop. I am ok with that. Plus I gain better point blank range and higher vel impacts throughout the range.

Steve

 

[Rich Coyle]

Steve,

Sound logical to me. Thanks for your research and bullets.

 

[codyadams]

That makes sense. I live at 6600 ft elevation, and I hunt at least this high or higher, up to about 9-10,000 feet, but I still went with a 1 in 8 twist on my 260 ai to shoot the 140+ weight bullets. I know matrix makes a 160 vld, but I'm kind of hoping Berger comes out with a 160 ish EOL line of 6.5 bullets, especially with the 26 nosler and other hot rods out. I'm shooting the 140 vld at 3115, so I think I could push a 160 at pretty fast speeds.