Tikka updating 300 wsm twist rate- 1-10”

[gerry35]

Sako / Tikka
Steyr
Mauser
CZ
Mosan Nagant
Lee Enfield
Bergara

Blaser
Shultz and Larsen
Heym
Sauer
Mauser
And a lot more.....

 

[BjornF16]

Forgive my ignorance on this topic, but is a bullet forever stable if it leaves the muzzle stable? For example, you shot those at 200 yards, is it possible the bullet won't behave that way at 600 yards?

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A bullet has its' least stability leaving the muzzle.

As a bullet slows down, the overturning torque trying to upset the bullet also decreases. However, the gyroscopic stability (rpm) doesn't decrease as much which acts to increase the gyroscopic stability of a bullet as it travels downrange.

Anything greater than SG = 1 is technically stable. The guidance for SG = 1.4 or greater is for "safety margin" (e.g. non-standard atmospheric conditions, imperfectly balanced bullets, errors in the SG prediction model).

The original Miller formula assumes a uniform bullet (i.e. no void in the nose). There is a modified Miller formula (used by JBM Ballistics in their online calculator) that takes into account the length of the plastic tip that the original Miller formula calculates as lead (or solid copper).

Even though the Miller twist rule has been shown to be accurate for a number of bullets (Miller 2009), it was not expected to be accurate for plastic-tipped bullets, and in fact predicts instability for many of them at commonly used velocities and twist rates where they are known to be stable.

https://arxiv.org/pdf/1410.5340.pdf

https://arxiv.org/pdf/1410.5737.pdf

 

[BjornF16]

I was driving through rural Austria not too long ago - I saw a deer stand in every field. I felt like I was back home, driving through bean fields in the southeast.

I'm not sure you're aware of this but Australia is not in Europe and Australia is probably up there with the US when it comes to long range shooting, hunting, and firearm ownership.

You do realize he typed "Austria" (in Europe) and not "Australia"?

 

[gerry35]

I'm not sure you're aware of this but Australia is not in Europe and Australia is probably up there with the US when it comes to long range shooting, hunting, and firearm ownership.

You must be trolling, Austria and Australia are different countries.

 

[BjornF16]

You must be trolling, Austria and Australia are different countries.

...and last time I checked, there was an awful lot of mountain hunting going on in Europe

 

[gerry35]

...and last time I checked, there was an awful lot of mountain hunting going on in Europe

I only guided mountain goats for two years but all my clients were from Germany, Switzerland and Austria and most were as good and guys from the U.S or Canada.

 

[Packmansion]

A bullet has its' least stability leaving the muzzle.

As a bullet slows down, the overturning torque trying to upset the bullet also decreases. However, the gyroscopic stability (rpm) doesn't decrease as much which acts to increase the gyroscopic stability of a bullet as it travels downrange.

Anything greater than SG = 1 is technically stable. The guidance for SG = 1.4 or greater is for "safety margin" (e.g. non-standard atmospheric conditions, imperfectly balanced bullets, errors in the SG prediction model).

The original Miller formula assumes a uniform bullet (i.e. no void in the nose). There is a modified Miller formula (used by JBM Ballistics in their online calculator) that takes into account the length of the plastic tip that the original Miller formula calculates as lead (or solid copper).

https://arxiv.org/pdf/1410.5340.pdf

https://arxiv.org/pdf/1410.5737.pdf

Dynamic Stability is much tougher to calculate. It depends on obscure coefficients that are hard to pin down. It's difficult to predict, and depends on subtle features of the bullet's design. Bullets can lose dynamical stability as they lose velocity. Unlike the case with gyroscopic stability, stability at the muzzle does not imply stability down range. Dynamic stability is referred to by a variable called Sd. Calculating the exact number is beyond the scope of this article - just know that it is hard to predict and requires a lot of data.

A bullet with "perfect" dynamic stability will have a Sd equal to 1.0. If Sd is less than or greater than 1.0, the bullet may become unstable. The safety margin for Sd depends on Sg. A bullet with a high Sg has more padding when it comes to Sd. A bullet that is on the ragged edge of gyroscopic stability will become dynamically unstable very easily.

 

[Packmansion]

You do realize he typed "Austria" (in Europe) and not "Australia"?

Lol just realized that.

 

[wirehead]

You do realize he typed "Austria" (in Europe) and not "Australia"?

I do.

 

[Packmansion]

Blaser
Shultz and Larsen
Heym
Sauer
Mauser
And a lot more.....

There are many more too. But the American bullet makers are driving the ship. You can't even buy Hornady or nosler in a lot of European countries. I think nosler is only sold in US and Canada. European consumer market is constrained to ammo that largely would not be beneficial for use in a 1:10. Technically 1:11 is more suitable for stubby bullets. You can get great stability out of partitions and a frames under all conditions. If Tikka is selling to finish people who cannot even buy an accubond or ELD-X a d they are shooting stubby cup n core bullets what insensitive is there to change other than American consumers.

 

[BjornF16]

There are many more too. But the American bullet makers are driving the ship. You can't even buy Hornady or nosler in a lot of European countries. I think nosler is only sold in US and Canada. European consumer market is constrained to ammo that largely would not be beneficial for use in a 1:10. Technically 1:11 is more suitable for stubby bullets. You can get great stability out of partitions and a frames under all conditions. If Tikka is selling to finish people who cannot even buy an accubond or ELD-X a d they are shooting stubby cup n core bullets what insensitive is there to change other than American consumers.

Rubbish

 

[gerry35]

Norma loads Nosler bullets in some of their factory ammo. Over at the Nosler Forum there are guys from Europe that load Nosler bullets and share their results with us. I would bet Hornady gets used over there a lot too.

 

[Gamehearse]

I agree fully. They could also discount them a bunch to move them. If the 1-11 I bought won’t shoot the heavier bullets I’ll re-barrel or stick to the 190-210 grain range which is probably where I would have ended up anyway.

I found my stainless T3x 300 wsm last fall at Smokey Mountain Guns and Ammo for $649. I should have known they were trying to move them for some reason…
It does shoot the 200 edlx’s 1/2 moa. That’s as heavy as I want to shoot in the 20” barrel anyway.

 

[Packmansion]

Norma loads Nosler bullets in some of their factory ammo. Over at the Nosler Forum there are guys from Europe that load Nosler bullets and share their results with us. I would bet Hornady gets used over there a lot too.

Well i guess Tikka/Sako have no good exuses

 

[Packmansion]

I found my stainless T3x 300 wsm last fall at Smokey Mountain Guns and Ammo for $649. I should have known they were trying to move them for some reason…

You can get a prefit and depending on your elevation and what you're doing it might not matter. If you're shooting factory stuff probably won't matter. If you reload it might not be ideal but it might still work. Anything 180 lead will work perfectly fine.

 

[wirehead]

This thread’s IQ was a lot higher when everyone was mindlessly complaining about their prized Tikka having a barrel that is limiting them from shooting big game at 1200 yards…

 

[BjornF16]

Dynamic Stability is much tougher to calculate. It depends on obscure coefficients that are hard to pin down. It's difficult to predict, and depends on subtle features of the bullet's design. Bullets can lose dynamical stability as they lose velocity. Unlike the case with gyroscopic stability, stability at the muzzle does not imply stability down range. Dynamic stability is referred to by a variable called Sd. Calculating the exact number is beyond the scope of this article - just know that it is hard to predict and requires a lot of data.

A bullet with "perfect" dynamic stability will have a Sd equal to 1.0. If Sd is less than or greater than 1.0, the bullet may become unstable. The safety margin for Sd depends on Sg. A bullet with a high Sg has more padding when it comes to Sd. A bullet that is on the ragged edge of gyroscopic stability will become dynamically unstable very easily.

Dynamic (as opposed to “dynamical”) stability is really only an issue in the transonic regime.

I don’t care about what bullet stability does at velocities below minimum bullet terminal ballistics velocities (~1800 fps for ELD-M)

 

[Packmansion]

Dynamic (as opposed to “dynamical”) stability is really only an issue in the transonic regime.

I don’t care about what bullet stability does at velocities below minimum bullet terminal ballistics velocities (~1800 fps for ELD-M)

Regardless of your application bullets are not stable forever once they leave the barrel.

 

[Packmansion]

This thread’s IQ was a lot higher when everyone was mindlessly complaining about their prized Tikka having a barrel that is limiting them from shooting big game at 1200 yards…

Sorry about that lol.

 

[wirehead]

I'm not sure you're aware of this but Australia is not in Europe and Australia is probably up there with the US when it comes to long range shooting, hunting, and firearm ownership.

Fitting…

Couldn’t help myself.