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JJD
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Location: Right Side WA state
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Burst Barrel!

Hey guys, I be need'in your help.

I have been a Hunter Ed istructor for a number of years.
Each year I have to explain that a firearm, fired with an obstructed barrel will burst the barrel.
Now explaining this to 12 year olds who have no concept of physics is a challenge. Most years, the students look at the photos and pretty much take my word for it.
I know the day is coming when a student will ask, well how come the bullet doesn't push the obstruction out of the barrel?

I need your help in coming up with a quick efficient way to explain this without a lot of complex physics language.

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Burst Barrel!

From what I have read lately, it seems to have more to do with the impact of the bullet into the obstuction. I was always told that the pressure spike was the culprit but new studies are showing the bullet fragmentation is a key player as well. Think

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Burst Barrel!

Fortunately that is an aarea I have NO personal experience in. Best of luck JJ.

bitmasher's picture
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Burst Barrel!

Good question. My two cents.

The projectile doesn't push it out because it instantly becomes deformed upon impact (while still in the barrel) effectively "wedging" it near the end of the barrel and allowing the pressure to spike way beyond limits in the few milliseconds following impact with the obstruction.

Some might say its not really "wedged" which is true, but the rate of moving forward (down the barrel) is far too slow compared to what it needs to be to relieve the pressure wave coming up from behind.

Its interesting to note, that when you have a load that is way, way beyond spec the barrel usually blows somewhere around the bolt head or chamber not the end of the barrel. Why? Because again the bullet can't move fast enough to relieve the very rapid pressure build up. This is also why you have over pressure vents in the bolt in some gun designs. The pressure (assuming it doesn't grow too quickly) vents through the primer and through the over pressure vents.

JJD
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Location: Right Side WA state
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Burst Barrel!

ChesterGolf,

I'd like to read some of the material you read on this subject.
While I have seen a barrel blown from dirt, I understand the same can occure as a result of snow. I have a hard time with a bullet impacting snow and causing fragmentation.
Unless this includes the pressure gradient issue, fragmentation would seem more of a bit player in the scenario.

I'm gonna do a bit of research on the web and see if I can find some articles there as well.

WesternHunter's picture
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Burst Barrel!

I think bitmasher may have hit on something here.

I've never had it happen to me, and I wouldn't try it on purpose either, but I've seen some tests done where burst barrel from an obsrtuction didn't result. In fact the projectile (smaller than bore diameter) was pushed out of the barrel with no real "noticeable" damage.

I have seen bursts with pistol and rifle barrels where an obstruction caused a tight seal in the bore. One that comes to mind I have seen an old GI 1911 barrel that split along the top from a .45 bullet that got stuck at the muzzle and one fired behind it. I would imagine any time there is no escape route for expanding gases, a high pressure situation will cause the barrel to burst. If there is room for those building gases to escape, the result maybe not so dramatic.

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Burst Barrel!

I'll keep looking but here is one article on it:

http://www.owenguns.com/important-firearm-information/exploding-barrel-b...

JJD
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Burst Barrel!

CGolf,
Read the article and it does have some merit.
Tried a little to find more articles, but there is so much unrelated material showing up in the search and it takes a while to wade through it all.

Thanks
JJD

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Burst Barrel!
JJD wrote:
CGolf,
Read the article and it does have some merit.
Tried a little to find more articles, but there is so much unrelated material showing up in the search and it takes a while to wade through it all.

Thanks
JJD

I know what you mean. I read a great article on this exact subject about 6mths ago and still haven't located it but I'll keep looking. It makes you look at the subject of burst barrels in a little different light if nothing else.

Don Fischer's picture
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Burst Barrel!

This is intresting. I've never given much though to my an obstruction might burst a barrel, just always heard it will.

But I''ve been thinking about it now. It would seem to me that the bullet hitting the obstruction will start to upset to some degree. That would increase the diameter of the bullet some degree and it would fit the bore to tightly. Be about like shooting an 8mm bullet in a 30 cal barrel. Wouldn't take much swelling of the bullet to buldge to barrel just a bit causing pressure to spike radically behind it. And once the barrel does bludge to bullet then fits even worse in the remaining barret and the pressure has to go somewhere; boom, barrel split.

Now if this same theory, and this is just a theory, was applied to fireing the 8mm bullet in the 30cal barrel, the barrel doesn't split, the action is blown apart. why? Well the bullet is contained inside the chamber area of the rifle which is much thicker that the barrel away from the chamber. The weakest link then becomes the action.

What do you think?

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Burst Barrel!

I think I'd rather not try it. Think

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