Your barrel life is 6 seconds

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Your barrel life is 6 seconds

Post by batter » 05 Jan 2014, 4:48 pm

I've cut this down a bit by removing a lot of the padding from the article, this was published on accurate shooter about the life of a rifle barrel measured in seconds.

Just a bit of fun trivia for us :)

If a bullet flies at 3000 fps, it will pass through a 24″ (two-foot) barrel in 1/1500th of a second. If you have a useful barrel life of 3000 rounds, that would translate to just two seconds of actual bullet-in-barrel operating time.

Your bullet starts at zero velocity and then accelerates as it passes through the bore, so the projectile’s average velocity is not the same as the 3000 fps muzzle velocity. So how long does a centerfire bullet (with 3000 fps MV) typically stay in the bore? The answer is about .002 seconds. This number was calculated by Varmint Al, who is a really smart engineer dude who worked at the Lawrence Livermore Laboratory, a government think tank that develops neutron bombs, fusion reactors and other simple stuff.

On his Barrel Tuner page, Varmint Al figured out that the amount of time a bullet spends in a barrel during firing is under .002 seconds. Al writes: “The approximate time that it takes a 3300 fps muzzle velocity bullet to exit the barrel, assuming a constant acceleration, is 0.0011 seconds. Actual exit times would be longer since the bullet is not under constant acceleration.”

We’ll use the .002 number for our calculations here, knowing that the exact number depends on barrel length and muzzle velocity. But .002 is a good average that errs, if anything, on the side of more barrel operating life rather than less.

So, if a bullet spends .002 seconds in the barrel during each shot, and you get 3000 rounds of accurate barrel life, how much actual firing time does the barrel deliver before it loses accuracy? That’s simple math: 3000 x .002 seconds = 6 seconds.

Six seconds. That’s how long your barrel actually functions (in terms of bullet-in-barrel shot time) before it “goes south.” Yes, we know some barrels last longer than 3000 rounds. On the other hand, plenty of .243 Win and 6.5-284 barrels lose accuracy in 1500 rounds or less. If your barrel loses accuracy at the 1500-round mark, then it only worked for three seconds! Of course, if you are shooting a “long-lived” .308 Win that goes 5000 rounds before losing accuracy, then you get a whopping TEN seconds of barrel life.

Anyway you look at it, a rifle barrel has very little longevity, when you consider actual firing time. People already lament the high cost of replacing barrels. Now that you know how short-lived barrels really are, you can complain even louder. Of course our analysis does give you even more of an excuse to buy a nice new Bartlein, Krieger, Shilen etc. barrel for that fine rifle of yours.

Original article with padding here.

Did make me worry for second about the cost of maintaining my stuff in the future if I'm replacing a barrel every 6 seconds :lol:
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Re: Your barrel life is 6 seconds

Post by Guliver » 06 Jan 2014, 5:55 am

That puts a whole new perspective on things.

Thanks
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Re: Your barrel life is 6 seconds

Post by Kater » 06 Jan 2014, 8:30 am

Interesting...

Bizarre though to think thousand dollar match barrels only have a few seconds of life too them.

Shoddy craftsmanship bastards :lol:
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Re: Your barrel life is 6 seconds

Post by Ken » 06 Jan 2014, 9:59 am

Kater wrote:Shoddy craftsmanship bastards :lol:


I can see the oldies chipping in with "When I was young barrels lasted 12 seconds!" :lol:
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Re: Your barrel life is 6 seconds

Post by Blackened » 06 Jan 2014, 10:05 am

I sense a bout of Monty Python's "Four Yorkshiremen" coming on :lol:
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Re: Your barrel life is 6 seconds

Post by fawksel » 06 Jan 2014, 10:08 am

FIRST YORKSHIREMAN:
Aye, very passable, that, very passable bit of risotto.

SECOND YORKSHIREMAN:
Nothing like a good glass of Château de Chasselas, eh, Josiah?

THIRD YORKSHIREMAN:
You're right there, Obadiah.

FOURTH YORKSHIREMAN:
Who'd have thought thirty year ago we'd all be sittin' here drinking Château de Chasselas, eh?

FIRST YORKSHIREMAN:
In them days we was glad to have the price of a cup o' tea.

SECOND YORKSHIREMAN:
A cup o' cold tea.

FOURTH YORKSHIREMAN:
Without milk or sugar.

THIRD YORKSHIREMAN:
Or tea.

FIRST YORKSHIREMAN:
In a cracked cup, an' all.

FOURTH YORKSHIREMAN:
Oh, we never had a cup. We used to have to drink out of a rolled up newspaper.

SECOND YORKSHIREMAN:
The best we could manage was to suck on a piece of damp cloth.

THIRD YORKSHIREMAN:
But you know, we were happy in those days, though we were poor.

FIRST YORKSHIREMAN:
Because we were poor. My old Dad used to say to me, "Money doesn't buy you happiness, son".

FOURTH YORKSHIREMAN:
Aye, 'e was right.

FIRST YORKSHIREMAN:
Aye, 'e was.

FOURTH YORKSHIREMAN:
I was happier then and I had nothin'. We used to live in this tiny old house with great big holes in the roof.

SECOND YORKSHIREMAN:
House! You were lucky to live in a house! We used to live in one room, all twenty-six of us, no furniture, 'alf the floor was missing, and we were all 'uddled together in one corner for fear of falling.

THIRD YORKSHIREMAN:
Eh, you were lucky to have a room! We used to have to live in t' corridor!

FIRST YORKSHIREMAN:
Oh, we used to dream of livin' in a corridor! Would ha' been a palace to us. We used to live in an old water tank on a rubbish tip. We got woke up every morning by having a load of rotting fish dumped all over us! House? Huh.

FOURTH YORKSHIREMAN:
Well, when I say 'house' it was only a hole in the ground covered by a sheet of tarpaulin, but it was a house to us.

SECOND YORKSHIREMAN:
We were evicted from our 'ole in the ground; we 'ad to go and live in a lake.

THIRD YORKSHIREMAN:
You were lucky to have a lake! There were a hundred and fifty of us living in t' shoebox in t' middle o' road.

FIRST YORKSHIREMAN:
Cardboard box?

THIRD YORKSHIREMAN:
Aye.

FIRST YORKSHIREMAN:
You were lucky. We lived for three months in a paper bag in a septic tank. We used to have to get up at six in the morning, clean the paper bag, eat a crust of stale bread, go to work down t' mill, fourteen hours a day, week-in week-out, for sixpence a week, and when we got home our Dad would thrash us to sleep wi' his belt.

SECOND YORKSHIREMAN:
Luxury. We used to have to get out of the lake at six o'clock in the morning, clean the lake, eat a handful of 'ot gravel, work twenty hour day at mill for tuppence a month, come home, and Dad would thrash us to sleep with a broken bottle, if we were lucky!

THIRD YORKSHIREMAN:
Well, of course, we had it tough. We used to 'ave to get up out of shoebox at twelve o'clock at night and lick road clean wit' tongue. We had two bits of cold gravel, worked twenty-four hours a day at mill for sixpence every four years, and when we got home our Dad would slice us in two wit' bread knife.

FOURTH YORKSHIREMAN:
Right. I had to get up in the morning at ten o'clock at night half an hour before I went to bed, drink a cup of sulphuric acid, work twenty-nine hours a day down mill, and pay mill owner for permission to come to work, and when we got home, our Dad and our mother would kill us and dance about on our graves singing Hallelujah.

FIRST YORKSHIREMAN:
And you try and tell the young people of today that ..... they won't believe you.

ALL:
They won't!
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Re: Your barrel life is 6 seconds

Post by batter » 07 Jan 2014, 10:03 am

Good old Monty Python.

I've got the Search for the Holy Grail sitting on my TV at the moment.

I reckon that's going on next time I'm sitting there cleaning my gear :lol:
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