rifling question

old owl

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I'm new at this so bear with me please.

where can I find information on the different twist and what they are good for?
example: is a 1 in 8" compatible with a light load or is it the opposite?

thanks for taking the time to read and answer
 
This info is from one barrel maker, and weight bullets can vary from whats listed
For example, I got the 1-13 twist 4 groove in .308 designed for 147 or so grain bullets, and it is excellent with 165/168 bullets
CALIBER TWIST IN INCHES ALL BARRELS ARE (6) GROOVES

.22RF 1 – 16

.204 1 – 8 , 1 – 10, 1 - 12

.224 1 - 8 VLD Bullets
1 - 9
1 - 10 ( All bullets, but best for hose heavier than 55 grains)
1 - 12
1 - 14 (bullets up to 55 grains)
1 - 8 VLD Bullets

6mm (.243 1 - 8 1/2 VLD Bullets
1 - 10 ( All bullets, but best for those heavier than 90 grains)
1 - 12, 1 - 13 (bullets up to 70 grains)
1 - 13 1/2 - (4 and 6 grooves)
1 - 14 - (4 and 6 grooves)
1 - 15

.257 1 - 10
1 - 12

6.5mm (.264) 1 - 8

.277 1 - 10

7 mm (.284) 1 - 9
1 - 10

.308 1 - 10 (All bullets, but best for those heavier than 168 grains)
1 - 12 (For bullets up to 168 grains)
1 - 14 (Benchrest Twist up to 168 grains)

.338 1 - 10

.38 special (.357) 1 - 14

BARRELS DISIGNED TO SHOOT I.V.I. AMMUNITION

.224 1 - 9

.308 1 - 13 (4 and 6 grooves)
 
Last edited:
I would suggest using the greenhill formula; twist = 150 diameter squared over length. Normally you would use 1" faster than the formula suggests.
The formula calculates the minimum twist necessary to stabilize a bullet of a given diameter and length and note that twist and length can be reversed so that if you know twist rate you can calculate the longest bullet that can be stablized.

cheers mooncoon
 
old owl said:
I'm new at this so bear with me please.

where can I find information on the different twist and what they are good for?
example: is a 1 in 8" compatible with a light load or is it the opposite?

thanks for taking the time to read and answer

Twist really has nothing to do with a light or heavy load. It has more to do with the length of the bullet... Longer bullets (which are usally heavier as well) require a faster twist to stablilze the bullet than shorter bullets require.

Just about all barrel makers will suggest what twist is best for the bullet you wish to use.

Here is a link to a page from Shilen's website:
http://www.shilen.com/calibersAndTwists.html


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