Average joe
Gold $$ Contributor
I've witnessed that "smoke" before at about 100 yards down range, but the bullet did not come apart.
Bullet blow up video
- Thread starter flintcreek6412
- Start date
That’s certainly interesting.... my score keeper swears he saw mine down range but didn’t see the blow up...had a couple guys watching my target in the pit so they didn’t make it there.
Last edited:
Alexander-M
Gold $$ Contributor
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
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
Spinning a bullet far too fast can make them come apart. Shooting thin-jacketed varmint bullets in a fast twist WILL make them come apart. A well-worn throat can sometimes make bullets come apart. Combine a well-worn throat, a bit of barrel heat, a fast twist and a projectile with a weak jacket and you very could well make puffs of gray.
Avoiding all of the above will insure that most of your projectiles reach the paper.
Avoiding all of the above will insure that most of your projectiles reach the paper.
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