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Twist Rates and Velocity?

 
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  #8  
Old 03-11-2013, 03:54 PM
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Re: Twist Rates and Velocity?

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Originally Posted by MontanaRifleman View Post
Actually barrel length has nothing to with how fast a bullet spins other than longer barrels usually produce more velocity which spin the bullet faster.

My question is for example, how much slower will a barrel with a 9 twist push a bullet then the same type of barrel with a 10 twist pushing the same bullet? 10 fps? 30 fps? 50 fps?
There is no real way to tell you exactly, unless you have full data to base off of your EXACT load and gun specs.
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  #9  
Old 03-11-2013, 04:03 PM
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Re: Twist Rates and Velocity?

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Originally Posted by MudRunner2005 View Post
You misunderstood....The bullet SPINS faster from a longer barrel BECAUSE there is more time it is touching the rifling and being acted upon by the rifling force for stabilization purposes. The rifling actually slows the bullet down slightly other than if it were a smooth-bore gun, b/c the rifling is actually biting into the bullet's jacket. So rifling has a very very miniscule affect on the velocity.
Nope. You better do some research on that. Length of barrel has zero to do with RPM's. It's the velocity.

A bullet coming out of a 22" 10 twist barrel at 3000 fps will spin just as fast as a bullet coming out of a 30" 10 twist barrel at 3000 fps.
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  #10  
Old 03-11-2013, 04:09 PM
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Re: Twist Rates and Velocity?

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Originally Posted by MontanaRifleman View Post
Nope. You better do some research on that. Length of barrel has zero to do with RPM's. It's the velocity.

A bullet coming out of a 22" 10 twist barrel at 3000 fps will spin just as fast as a bullet coming out of a 30" 10 twist barrel at 3000 fps.
SPINS....NOT TRAVELS! You keep misunderstanding what I'm saying. We are saying the same thing... I never said a longer barrel had crap to do with velocity.

VELOCITY comes from the load itself. Stability comes from the rifling and barrel length, which improves accuracy down range.
__________________
"I'm just a peckerwood who lives in the hills with too many guns..." - Bob Lee Swagger

"Give me a minute...I'm good. Give me an hour...I'm great. Give me 6 months...And I'm unbeatable." - Col. Hannibal Smith

Ignore everything I say, because I have a reading comprehension and memory problem...

Quote:
Originally Posted by WildRose View Post
The 284 is to the STW what a tricycle is to a Ninja.
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  #11  
Old 03-11-2013, 04:16 PM
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Re: Twist Rates and Velocity?

Quote:
Quote:
Originally Posted by MudRunner2005 View Post
SPINS....NOT TRAVELS! You keep misunderstanding what I'm saying. We are saying the same thing... I never said a longer barrel had crap to do with velocity.

VELOCITY comes from the load itself. Stability comes from the rifling and barrel length, which improves accuracy down range.
Someone is misunderstanding someone.... Spins = RPM's

How fast a bullet spins is dependent on twist rate and muzzle velocity only, not barrel length.... which isn't the question I'm asking.

Tighter twist puts more resistance on a bullet and it will increase pressure and reduce velocity, or reduce velocity with the same pressure.

The max load muzzle velocity for bullet coming out of a 9 twist is going to be slower than the max load velocity of the same bullet coming out of a 10 twist.
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  #12  
Old 03-11-2013, 04:23 PM
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Re: Twist Rates and Velocity?

I give up. We're talking about the same thing, but for some reason this is not getting through....

Done. Out. Over it. Good luck.
__________________
"I'm just a peckerwood who lives in the hills with too many guns..." - Bob Lee Swagger

"Give me a minute...I'm good. Give me an hour...I'm great. Give me 6 months...And I'm unbeatable." - Col. Hannibal Smith

Ignore everything I say, because I have a reading comprehension and memory problem...

Quote:
Originally Posted by WildRose View Post
The 284 is to the STW what a tricycle is to a Ninja.
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  #13  
Old 03-11-2013, 06:30 PM
Edd Edd is offline
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Re: Twist Rates and Velocity?

The 6mmBR website says............

Does Twist Rate Make a Difference in Velocity? Yes. Our tests show that, with the 80-90gr bullets, a 1:10 or 1:12 barrel will give you as much as 80fps more velocity than a 1:8 barrel, shooting the exact same loads.
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  #14  
Old 03-11-2013, 11:41 PM
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Re: Twist Rates and Velocity?

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Originally Posted by Edd View Post
The 6mmBR website says............

Does Twist Rate Make a Difference in Velocity? Yes. Our tests show that, with the 80-90gr bullets, a 1:10 or 1:12 barrel will give you as much as 80fps more velocity than a 1:8 barrel, shooting the exact same loads.
Thanks Edd, that is exactly what I'm looking for.

Any other experience or knowledge is much appreciated.
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