.270wcf vs 6.8 Western & 270 WSM

[Western4444]

You need the twist to keep the bullet flying point forward. Twist rate has zero to do with retained energy.

The faster the twist, to some point, will increase the BC of the bullet. A higher BC bullet is not impacted as greatly by the wind. A higher BC bullet does better in the wind then a low BC bullet. You can test....do a ballistic calculation on a same weight bullet with two different BCs, high and low, with a 10 mph wind. As pointed out a higher twist rate stabilizes high BC bullets.

 

[FEENIX]

One can shoot these heavier hi twist bullets (165, 170 and 175 gr) in a 270 WCF, but accuracy will be terrible at best. And energy at 400 yards or more will be a fraction of a faster twist barrel. The faster a bullet twist, the more energy the bullet retains at longer distances. I don't want to say it is simple math, but is a straight forward physics problem.

HUH?

You need the twist to keep the bullet flying point forward. Twist rate has zero to do with retained energy.

Yep!

 

[FEENIX]

The faster the twist, the less resistance a bullet has traveling through the air. A high twist bullet is not impacted as greatly by the wind. A higher BC bullet does better in the wind then a low BC bullet. You can test....do a ballistic calculation on a same weight bullet with two different BCs, high and low, with a 10 mph wind. If a bullet could spin fast enough, the only force on it would be gravity. Of course only theoretical. We could reach reach that bullet rotation.

This is not a true statement. I think what you meant to say is that a high BC bullet has less resistance through the air - bucks the wind better than a lower BC bullet. Twist rate is a requirement to meet the minimum SG of 1.5.

Here's a good refresher source on why barrel twist matters...

https://bergerbullets.com/shoot-better/shooting-knowledge/why-does-barrel-twist-rate-matter/

 

[Western4444]

i enjoyed your coyote photos.

I think we are saying the same thing. The the fast twist bullet experiences less resistance, so it maintains its momentum (energy) to longer distances.

I love the 270 WCF and it excels with bullets to 150 gr, but one needs the faster twist barrels to shoot these heavier bullets. I am thinking about rebarreling a 270 with a 7 1/2 twist barrel to shoot these heavier bullets.

 

[FEENIX]

i enjoyed your coyote photos.

I think we are saying the same thing. The the fast twist bullet experiences less resistance, so it maintains its momentum (energy) to longer distances.

I love the 270 WCF and it excels with bullets to 150 gr, but one needs the faster twist barrels to shoot these heavier bullets. I am thinking about rebarreling a 270 with a 7 1/2 twist barrel to shoot these heavier bullets.

Yes, except for this ...

The faster the twist, the less resistance a bullet has traveling through the air. A high twist bullet is not impacted as greatly by the wind.

... again, the twist rate is for bullet gyroscopic stabilization.

 

[Western4444]

This is not a true statement. I think what you meant to say is that a high BC bullet has less resistance through the air - bucks the wind better than a lower BC bullet. Twist rate is a requirement to meet the minimum SG of 1.5.

Here's a good refresher source on why barrel twist matters...

https://bergerbullets.com/shoot-better/shooting-knowledge/why-does-barrel-twist-rate-matter/

This is a good video on BC by Ron Spomer ...

l like the way he explains when BC is important and when not.

I fully agree, faster twist stabilizes the high BC bullets. BC is the primary factor in the energy equation.

I appreciate the dialog we are having, we are adding value.