I am setting up a 338-06 that will not shoot any bullet heavier than 225 or lighter than 200gr. I am told that 1:14 would be the best twist. Assume bullets to be factory Nosler Partition and or Accubond.

What are your thoughts? I have read that 1:12 was pretty standard but that could be just so it could handle the heavier bullets?

Length of the bullet, not weight, is the determining factor at arriving at the amount of twist needed to stabilize the bullet.

I've had a number of 338-06 put together over the years and I've ALWAYS gone with a 10" twist and never had any complaints. Accuracy has been acceptable to excellent through the range of bullet weights...

Moreover, It is my understanding taht the 10" is the standard for the 338-06 and 338 WM, not the 12"...

I MIGHT use a 12", but I would avoid the 14"

JMO...

I don't know what brand of barrel you are going to use, but Hart only offers their 338 bore barrels with a 10" twist.

I am using a pre-64 std 24" barrel and having it rebored. Are these slower twists like 10" used to handle the much heavier/longer bullets? As I mentioned I do not want to shoot anything heavier than 225 gr and I know many begin with 250's and move up which is not my program.

I appreciate the input and your experience.

Ruger MK11 in .338 WM is 1in 12" shoots from 160 Grn 300 Accurately enough for any hunter !

quote:

Originally posted by muygrande:
I am using a pre-64 std 24" barrel and having it rebored. Are these slower twists like 10" used to handle the much heavier/longer bullets? As I mentioned I do not want to shoot anything heavier than 225 gr and I know many begin with 250's and move up which is not my program.

I appreciate the input and your experience.

Ummm... 1-10 is fast twist, 1-14 is slow twist. Read it as 1 turn in xx inches, the fewer inches/turn the faster the twist rate.
a 200gr boattail spitzer may need a faster twist than a 225gr flatbase roundnose.
Also remember that the twist rate you see published (or calculate) is the MINIMUM that will stabilize the bullet, using a faster twist rate (within reason) won't hurt anything and may be of benifit to you.

I appreciate your proper reading of my error. Sometimes the fingers work faster than the brain.

This page provides the reference numbers. If you stay with these recommndations, you'll be safe.

As Rick pointed out above, it is actually bullet length (and velocity) as opposed to bullet weight which determines the twist rate you need. That means people are some times able to stabilize bullet weights with barrel twist rates outside what the table specifies. That is just part of the game. Besides, you never know whether a bullet reported stabilized is a RN, a spitzer or how long it was...

Stay with the data listed in the link above, and you'll be fine.

- mike

Thanks for the link and info. Looks like 10 is THE number. Certainly glad I stopped by the visit with the experts.

In practical terms length and weight of a bullet (within a given caliber) pretty much go hand in hand in most instances, but depending on bullet shape and type it isn’t always the case.

I was taught that if you are going to slightly err in twist rate you should err on the faster side since there is really no such thing as an “over-stablized†projectile...within reason of course.

I checked the A-Square standardization for the .338-'06 S-Square that they submitted to SAAMI, and the twist was 10" RH.

jim