Video of Bullet Blow Up (was: The things one sees at a match)

[Monte F]

One of our shooters here was vaporizing bullets in his fast twist 22dasher late in the strings as things heated up. We were getting the "mark target #( )" call in the pits before someone spotted the gray cloud and strange noise about 25 yards out. We now know what to look for when you get the no shot shown and no crossfire call.

 

[Evan]

You know, I thought about this more, and in retrospect I'm 99.9% sure I've had issues with the 147s coming apart recently. That said, I'm leaning towards it being specific lots of bullets having the problem.

About 6-8 months ago I purchased 1,000 of them from Midway, and lucky me, I got 10 individual 100rd boxes, comprised of about 8 unique lots. Much to my surprise they measure/weigh very consistently, and shoot way better than a 30-cent bullet should. On one lot however, I had some major issues.

Went shooting with my dad (this is memorable, because it's probably the 2nd-3rd time it's happened in my life) and wanted to introduce him to LR shooting. We set a 12" gong up at 400 yards on a hot, no-wind day (an absolute cake walk of a shot right?). The only thing different about this day was I was fire forming new brass, and had loaded yet another new lot of those 147s.

999 times out of 1000 I'd expect to first round hit (or at the very least 2nd round hit) a plate at that distance. I shot 22 rounds (holding different edges of the plate etc.)and didn't hit it once. In fact, I couldn't spot impacts on a dirt backstop on the shots. At the time it was somewhat embarrassing, but more than that it was frustrating as hell because I couldn't explain what was happening. I ended up pulling the bullets and dumped them in a coffee can somewhere.

In retrospect, my father wouldn't have known what to look for, and there's a minuscule chance you're seeing a blow up from behind the rifle.

I've since shot the 147s (a different lot than mentioned above), and they shot very well; out of the same barrel only with a higher round count for that matter. In fact, a crappy 'sharpshooter' rated LR shooter like me had such good luck with them this past weekend, I ordered 2,000 of them (and 1k 140 Hybrids, thank god) on the drive back home from Houston.

This thread, and the realization above makes me nervous as hell about that purchase.

I bought a whole crate of 147s, 2300 of them, and haven't had any problems at 2750fps out of a 6.5 Creedmoor 7.7 twist RPR.

Now 88ELDS...I blew them up like it was going out of style a couple weeks ago at a 1000yard match out of my 22BR. 2950fps out of a 7twist 5R Bartlein. I brought 100rnds to the match and I don't think half of them made it on target across 6 relays: http://forum.accurateshooter.com/threads/my-new-22br.3981971/page-2#post-37548898 Apparently I put on a great show. It was an informal match and after everyone else finished their relay they just watched me shoot and shoot, trying to get 5 on target for record. It starting after about 10 rounds, and continued for the rest of the match. It was rather disappointing.

 

[Alexander-M]

This happened to me May 2018. Brian Bowling filmed the video.

My response a few days later:
-------------------------------------------------------------------------------------------
I apologize for not posting this before - I wrote it up, thought I had posted it, and saved the original. Just realized my oversight today.

Plausible Explanation for the Blowing Up Bullets
(If you do not want to read all the details, here is the conclusion.)

• The bullets got too hot, the lead melted, which caused the jackets to crack and the bullets to disintegrate or blow up
• The most common cause for the bullets to get too hot is a barrel that is too hot. (*)

Please note that I had shot 300 rounds prior to this day with that barrel, using the same loads, and did not have any problems. After a close examination of the barrel, it was concluded that there was nothing wrong with it. Not long after that, I shot 200-15X and 200-10X at 600 yards with bullets from the same lot, and same loads.

A few days after the occurrence, I talked with reps from Sierra, Berger, Krieger, and Lapua, and with my gunsmith. Most would not say they were 100% sure, but they doubted that the barrel would be the culprit. The rep from Berger and my gunsmith concurred without doubt on the source of the problem: (*) the bullets got too hot; the lead melted, expanded, and cracked the jackets as the result of the barrel being too hot.

This phenomena was analyzed in an experimented conducted by MIT, in conjunction with Berger, many years ago using thermal imagery and high-speed cameras. After that, Berger started using thicker jackets for the match bullets – not the hunting bullets.

The bullets get hot due to friction in the barrel and on its way to the target, and in some cases a barrel that is too hot can exacerbate the condition, which can cause the failure.

Was my barrel too hot that day?
Oh, yes! And here is why –

That match consisted of 60 rounds (3 x 20) shot on Saturday, plus 40 rounds (2 x 40) shot on Sunday.

We had wind and flying popup canopies during the first two 20-round matches on Saturday, which slowed things down a bit. That first day there we had at least four shooters on most targets, and we also had a brief rest between the first two matches. After the second match, the rains came, and we had a one-hour delay. By the time we shot the third 20-round match, the barrels had cooled down.

Sunday started without any problems, but several of the shooters had left, and some targets, such as mine, had only three shooters. Things got underway rather well, and we started shooting.

Not long after I shot the first match of the day, my turn came up to shoot again rather quickly – my final match of the event. My friends Brian and his wife Amanda helped me move some of my stuff to the firing line. As I went to pick up my rifle, I inadvertently brushed my hand against the barrel, and immediately uttered and expletive. Amanda said, “Still hot, isn’t it?” Yes, it was sizzling hot.

If I recall correctly, after converting my second sighter, I tried to shoot fast, but after a couple of rounds, I shot two or three 9’s, so I decided to go back to my normal pace. I had the wind figured out, and resumed shooting 10’s and X’s. But with just a few rounds to go, I scored a 7, and then a 6! Whoa! Something must be wrong with the SM Target, I said out loud. One of the other shooters then said, “Alex, your bullets are blowing up”. Inexperienced as I am, I had never heard of such thing, and was in disbelief.

Then he showed me a video he had just taken with his phone, which showed the bullet blowing up. Wow! At this point Brian asked me if I had any rounds from the previous day, which I did. I shot two more rounds from Saturday, the bullets did the same thing, and Brian videoed one of the shots.

...and that's the rest of the story...

Alex
------------------------------------------------------------------------------------------------
The entire thread:
http://forum.accurateshooter.com/threads/bullet-blow-up-video.3952995/

 

[spclark]

For me... only the RSAUM has pushed match grade bullets fast/hard enough to explode them.

The Schneider 1:8 on the T2k I bought in 2004 would blow up Berger 115VLD's.

I was a relative newbie to shooting rifles back then so knew little to nothing about bullet length vs. stability. And I wasn't pushing them particularly fast either! To this day I suspect the grey clouds observed by my scorers were because they were tumbling just after leaving the muzzle.

I never finished that string either. After two 'misses' it just wasn't worth it anymore.

 

[davidjoe]

The Schneider 1:8 on the T2k I bought in 2004 would blow up Berger 115VLD's.

I was a relative newbie to shooting rifles back then so knew little to nothing about bullet length vs. stability. And I wasn't pushing them particularly fast either! To this day I suspect the grey clouds observed by my scorers were because they were tumbling just after leaving the muzzle.

I never finished that string either. After two 'misses' it just wasn't worth it anymore.

You sure started out right with a rifle like that. Yeah, the 7 Saum case I credit with being able to overpower bullets because slow twist, or fast twist, any brand bullet, weight or barrel, I’ve found it capable of exploding bullets prior to significant case head damage. Heck my last no reads were before the barrel even heated in sighters. Other cartridges might have a magically bad combination of variables, but I suspect I can get any of my Saums to blow up any match bullet without hard bolt lift.

 

[johnnyi]

The video is approaching 1000 views. You folks just can't seem to get enough of it.

I'm also shocked at how often this seems to happen. I have not figured out why a few degrees hotter outside would make a difference. Especially since we all use extreme temperature insensitive powders.

You are almost a YouTube sensation..! You had better lockdown your sponsors

 

[Dusty Stevens]

Well, we shot in a Haboob one day while firing 3 to a mound. That was a challenge up until they shut the range down. Picked fine red sand out of my gear for the next 4 or 5 years. I have experienced wind like that in a microburst.....

SA is now a first class S-hole that I would only go to if I could carry an MP-5 and a backpack full of mags. It was bad in 99 and now it is infinitely worse. There are pages on Facebook devoted to murders of Caucasians and Caucasian farmers especially.

Its a damn shame too. Rediculous.

 

[Turbulent Turtle]

You are almost a YouTube sensation..! You had better lockdown your sponsors

Yeah, well the video is not on YouTube, they would probably censor it, that's why it's on Nikon Image Space along with all my other pictures for sharing.

Do you really think I could make a living at this? I'm skeptical.

Oh, and I did reach 1000 views this weekend. You can hear the virtual champagne bottle popping.

 

[Turbulent Turtle]

For me, TT, only one caliber has been capable of exploding target bullets. From .223 to 50 BMG, some 50 competition-capable rifles I maintain at a time in ~10 cartridges, optimized for heavy-for-caliber bullets, only the RSAUM has pushed match grade bullets fast/hard enough to explode them before the case head expands and releases the primer. Like you, I don’t shoot 6.5’s so I have no info on them.

Example, there is 100% overlap in bullet choice between .284 Win and Saum. I shoot blue, yellow, red and green boxes. My .284’s have not blown up a single one of any of them, and I’ve pushed them brass-smashing hard at times, surprise. Since premature brass destruction with heavy loads of slow magnum powders is the absolute speed limit, at least in my experience a .284 will not explode a bullet.

On the other hand I have “immolated” all except green box bullets in Saums. The relative fragility is red, blue, yellow, then yellow’s special - “orange”, now.

There is 100% overlap between .308 and 300 magnum match bullet choices. Neither cartridge, not even the fastest 300 Winchester loads has blown a bullet.

Aside from match calibers, I haven’t been able to blow up a bullet in some 15 other calibers between .17 and 30-378. My varmint loads go up to an estimated 4,500 FPS in my 6 Remington AI. Not one lost. Of course I don’t heat these up as much as 25 round shot strings do, either, though.

But I’ve heated .338 LM barrels in matches hot enough to steam and almost ignite alcohol soaked hand towels mid-string, and they as well have never blown up a yellow or blue box bullet.

That’s how “special” the Saum truly is. It doesn’t kick at all in a 22 pound rifle, it forgives ho-hum wind calls and it tempts you to push it harder but it’s a sports car without built-in active electronics to save your butt in a turn, because it absolutely can unpeel contemporary bullets.

So, let me ask you this. Have you hosers ever heard of barrel coolers or chamber chillers? You know, devices that cool down your barrel between relays?

Are you also aware that shooting in super hot barrels is how you destroy barrels in the first place?

We're going to have a discussion in Raton right after we win the team match competition.

 

[Turbulent Turtle]

This happened to me May 2018. Brian Bowling filmed the video.

My response a few days later:
-------------------------------------------------------------------------------------------
I apologize for not posting this before - I wrote it up, thought I had posted it, and saved the original. Just realized my oversight today.

Plausible Explanation for the Blowing Up Bullets
(If you do not want to read all the details, here is the conclusion.)

• The bullets got too hot, the lead melted, which caused the jackets to crack and the bullets to disintegrate or blow up
• The most common cause for the bullets to get too hot is a barrel that is too hot. (*)

(big snip)

I'm a little confused by your statement that the lead melted and this caused the jackets to crack.

Bullet jackets are made of gilding metal which is 95% copper and 5% zinc. Copper (Cu) has a melting point of 1084 degrees Celsius, which is almost 2000 F. Lead (Pb) has a melting point of 327C or 620F. I fail to see how melting lead would cause copper to crack.

We also have to understand that the time in the barrel is measured in microseconds when firing the round, which is what would cause the bullet to heat up. Of course, if you're telling me that you like to cook your bullets before shooting by leaving them in the chamber for a long time, I will come back and say that if your firing rate is slow enough to allow a bullet to reach even 1000F, let alone 1000C, you're not shooting at a fast rate.

I would also say that if your bore is that hot that it is able to actually melt the gilding medal, your rounds would be cooking of in the chamber and the wood stock would probably be on fire, which might impact your marksmanship and create some mirage effects for the riflescope.

Also, since cartridge brass is 70% copper and 30% zinc and zinc has a much lower melting point than copper, the cartridge cases in your chamber are getting annealed just prior to the cook-off.

 

[Ned Ludd]

http://forum.accurateshooter.com/threads/comet-tails.3972620/page-2

Micro-cracks in the jacket created during the forming process, creases or nose folds that become cracks through the torsional strain induced when they enter the rifling...I can think of a lot of possible ways the cracks or perforations in the jacket could come about. I'm not even sure the "how" is all that important, as it obviously occurs. As lead from the surface of the core becomes locally heated and vaporized, it sprays out and the bullet will become more and more unbalanced, leading to further strain on it. I can easily envision how this can be viewed as "promoting" the failure process. At spin rates of 200,000 to 300,000 RPM, even a very small imbalance can cause a big problem, as anyone that's ever loaded and run an ultracentrifuge can tell you.

 

[Alexander-M]

Denys,

I was only quoting, as well as I could remember, what the Berger technician told me.

This article explains the phenomena in more detail:
https://bergerbullets.com/history-of-the-match-grade-berger-hunting-vld/

An excerpt from the article:
"As it turns out, the bullets were heating up to the point where the cores would actually melt. Once a bullet leaves the barrel with a melted core, it is certain that the molten lead will burst through the jacket under such high RPM. Obviously this was a problem that we needed to resolve, so we decided to test a thicker jacket. Making the jacket thicker did not make it strong enough to contain molten lead; but rather, it moved the lead away from the source of the heat. The source of the heat that can melt a core is the friction between the bearing surface and the rifling as the bullet travels through the barrel."

Alex

 

[Turbulent Turtle]

http://forum.accurateshooter.com/threads/comet-tails.3972620/page-2

Micro-cracks in the jacket created during the forming process, creases or nose folds that become cracks through the torsional strain induced when they enter the rifling...I can think of a lot of possible ways the cracks or perforations in the jacket could come about. I'm not even sure the "how" is all that important, as it obviously occurs. As lead from the surface of the core becomes locally heated and vaporized, it sprays out and the bullet will become more and more unbalanced, leading to further strain on it. I can easily envision how this can be viewed as "promoting" the failure process. At spin rates of 200,000 to 300,000 RPM, even a very small imbalance can cause a big problem, as anyone that's ever loaded and run an ultracentrifuge can tell you.

Yep, understood. Considering that copper transmits heat 20 times faster than steel, one can see how the heat generated by the friction in the barrel would be rapidly transmitted to the lead core to cause it to melt.

I would also think that the bullet is not going to cool down rapidly going through the air, in fact, it will stay hot. I remember reading that the SR-71 at altitude (80,000+) and at Mach 3.2+ would generate temperatures of 600F on the windows and 1000F on the spikes and nose. So a bullet at see level starting off near Mach 3 coming out of the barrel with a molten core will easily keep that temperature in the .5 to 1.5 second flight time.

I don't hunt much, but the pictures of retrieved cup & core bullets that I have personally seen or seen pictures of, do not show the core to have been molten when it reached the target. The same with shots on steel; there is a splash but you can still find the core and I have seen videos of bullets on steel coming back at the shooter.

I also saw some comet trails from some of CPerry's bullets, but they still got to the target at 1000 yards and they were still under control as he was hitting in the black. One would think that if there was a leak it would create a dynamic instability on the bullet, causing it to go haywire, but these were not affected.

I will also add that shedding material during flight will dramatically change the BC of the bullet as the SD diminishes. The bullet would fall short and may never be detected.

 

[davidjoe]

Polymer tipped bullets on prior generation Hornady bullets were discovered via Doppler radar tracking to sometimes have melted in mid-flight from friction, with the blunted nose causing an abrupt down-step in BC.

 

[Turbulent Turtle]

Polymer tipped bullets on prior generation Hornady bullets were discovered via Doppler radar tracking to sometimes have melted in mid-flight from friction, with the blunted nose causing an abrupt down-step in BC.

Here we go away, pounding away on Hornady bullets. I know they are horrible, but is this really necessary?

Answer is: Yes, very much so.

 

[ShootDots]

Here we go away, pounding away on Hornady bullets. I know they are horrible, but is this really necessary?

Asnwer is: Yes, very much so.

Hey Denys! There is nothing wrong with Hornady bullets>>>>> as long as you don't own or shoot them! LOL!!!

 

[Turbulent Turtle]

Hey Denys! There is nothing wrong with Hornady bullets>>>>> as long as you don't own or shoot them! LOL!!!

Do you mean that they are fine bullets, in someone else's rifle?

You're just plain mean.

 

[rardoin]

I recently heard it said that the Hornady ELD-M's are guaranteed.....guaranteed a few 9's in every box.

 

[davidjoe]

The ELD M’s came with higher temperature tips. In 180’s, I just saw this past Sunday another example of the jacket fragility issue play out in the South Texas heat. Granted we have 100-3 degree heat every day of the week and are basically lateral to Miami, but the cartridge was a .284. Not suggesting his was the first .284 to unwrap these, but a lot of guys haven’t burst any in a .284. However, this would be the absolute smallest cartridge you would expect to shoot these from. If the smallest cartridge doesn’t have much headroom for hot days, barrel variations or speed, then use at your own risk in anything bigger. I had to stop using them in Saums myself in late 2017, after being quite satisfied with accuracy results.

 

[Turbulent Turtle]

Well, I never exploded any of my JLKs, in either .224 or .308. Of course, Swampy used J4 (Berger) jackets, but in the last few years he was using another supplier.