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Fast rate of twist?
- Thread starter Shubey
- Start date
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Lonewolf74
Well-Known Member
- Joined
- May 12, 2016
- Messages
- 735
Just to keep in mind a bullet spun faster also wobbles more just like an out of balance wheel on your car vibrating more as you go faster.
So just like every thing else there are trade offs. In general slower twist will be more accurate given they're sufficient twist to stabilize the bullet your using.
So just like every thing else there are trade offs. In general slower twist will be more accurate given they're sufficient twist to stabilize the bullet your using.
Yep! It will
Good to know!
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I think faster spin would have more shock transmitted to animals. My 2cents!??????????
Might want to wait and see what shoots in your rifle. I have a 6.5 twist .22 CM and never shoot projectiles lighter than 80.5 gr. I do have a box of 73 gr Hammer Hunters to try. You might be putting the cart before the horse deciding on projectiles before loading some up and trying them. You may find one bullet that does it all. If it kills a deer more than likely it will kill a dog.
What is your build on?
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Rem. 700 SA,Shilen match,SS, 25", Sendero Taper,magpul stock.
Rem.700 SA, Shilen SS Sendero contour,match barrel , magpul stock.
Kinetic energy is directly proportional to the mass of the object and to the square of its velocity. K.E.=1/2 M V2.
In a nutshell it comes down to bullet weight/diameter (mass) and speed (fps) for the energy hitting the animal. Twist rate will help the bullet stabilize and help with accuracy (super sonic, trans sonic, sub sonic). When calculating "Energy" it all comes down to mass and velocity.
So...rotational spin, is out of the equation?
You will probably have others with much more knowledge than me on Ballistics. Some might say the bullet spinning faster will make the bullet expand more upon hitting tissue. If you look at physics a bullet traveling at 3,000 fps with a twist rate of 1:8 will have the bullet spinning at 135,000 rpm. (correction 270,000 rpm missed by 2x value).When the bullet enters the animal going 3,000fps it will take approximately 1/3000 of a second to go through 1' of the animal. Now it is going to be slowed down by body tissue and even stopped. If the bullet was not stopped or slowed by the animals body tissue it would spin 2,250 (correction 4,500) times per second in that 1' going through the animal.
I would say that the bullet "Mass" x "Velocity" equals the "Energy" of the bullet hitting the animal and that the "Spin" of the bullet has little to do.
My calculations may be off, but wanted to break down in simplest form to understand Mass and Velocity being the main part of Energy and showing twist rate and how fast everything happens when a bullet leaves the barrel and then hits an object.
EDIT
I was off on my calculation for RPM. I should not Post before going to bed and start using a calculator instead of just doing in my head.
The formula to calculate a bullet's RPM is equal to Muzzle Velocity (fps) x 12 inches x 60 seconds / Twist Rate (inches).
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Ckleeves
Well-Known Member
Bullet RPM is fps x 720 / twist rate. So at 3000 fps with a 8 twist you're looking at 270,000 rpm. This is where you can overtwist, let's take a 55 grain bullet out of a 22 creed. Let's say you push it 3800 fps so 3800 x 720 / 6.5 your over 420k. That's cooking, quite a few bullets won't hold together at that rpm.
