Twist Rate

[Partyguy816]

I just bought a CZ 550 Varmint .308 which has a rate of twist of 1:12".

I bought some bullets from midway that were Hornady 155 grain A-Max and on the box it says Twist Rate 1:14" or faster. I don't know a lot about the twist so is my rate faster or slower? I would tend to think mine's faster, but what happens if you use a slower twist with this bullet?

Thanks

 

[Jimmie]

1:14 means one rotation in 14". 1:12 means one rotation in 12". So the 1:12 is faster. Hornady's warning is because they say a slower rate won't stabilize the bullet. Too slow = won't stabilize. Too fast = won't hold together.

 

[Partyguy816]

Thanks, I figured out what I was asking and I came to delete the post, but ya beat me to it. Oh well, someone else may want to know someday.

Thanks

 

[Hunter0924]

Twist rate has to do with bullet length. The longer the bullet the further away the center of force is from the center of gravity so a faster twist is needed to stabilize.

 

[OLD DOMENION]

This should help:

Start a tight patch; being sure the jag is tight on the rod.
Mark the rod with a felt tip to indicate Top Dead Center and a starting point.
Advance the rod until it comes back to Top Dead Center.
Measure the distance traveled from the start mark. That is the rifling twist, one turn in xx inches.
A lot easier than trying to estimate the amount of twist in a foot.