Twist rate

[Wachsmann]

In the future I want to get my Sendero rebuilt. I'll be going with the 7mm ultra mag for my choice. I would like to primelry set the gun up to shoot the 180 VLD's for long range. What is the preferred twist rate or best twist rate and length of barrel to get the best performance out of this combo....any experienced or susgestions are welcome. The gun I currently have is a 300 ultra mag.

 

[7stw]

In the future I want to get my Sendero rebuilt. I'll be going with the 7mm ultra mag for my choice. I would like to primelry set the gun up to shoot the 180 VLD's for long range. What is the preferred twist rate or best twist rate and length of barrel to get the best performance out of this combo....any experienced or susgestions are welcome. The gun I currently have is a 300 ultra mag.

A 1 in 9 is said to be adequate for 180 bullets.

 

[Greyfox]

I'd go with a 1:9 for the Berger 180's.

 

[BEEMAN]

1:8 for the upcoming 195 Berger.

 

[wyld]

A 1:8 should work. You can calculate the exact twist rate by using formulas from various sources. The best source I have found is from the book, "Sporting Firearms, A Designers Notebook" obtainable from Amazon.com It has a companion CD with several programs, one of which has the most popular twist formulas which allow you to enter the data and the program produces the result for you.
RF