Does anyone know of a reliable source of information on the twist rates in factory rifles? Do the firearms manufacturers have a standard that they use or do different makers use different twists?

Don't know about the current edition, but Lyman's Cast Bullet Manual (I have the 3rd edition) has twist rates for both rifle and pistol.

Since factories have no idea what bullet you will be using they normally standardize a twist rate that will stabilize the longest bullet for a given caliber.

Most custom makers offer a choice of twists for each caliber so you can match it more closely to your specific bullet.

Most of the rifles I own are factory built. I was just wondering if there was a reference source that listed the twist that they came with. It would be nice to know that as I am experimenting with different powders, bullets, etc. I know that I can get pretty close using the cleaning rod method.

quote:

Originally posted by hvy barrel:
Most of the rifles I own are factory built. I was just wondering if there was a reference source that listed the twist that they came with. It would be nice to know that as I am experimenting with different powders, bullets, etc. I know that I can get pretty close using the cleaning rod method.

You should also be aware that an advertised twist rate is not always “exactly†as advertised either depending on the method used to rifle the bore. The tooling used in button rifling can sometimes slip just a bit and the actual twist can vary up to a half inch or so.

quote:

Originally posted by hvy barrel:
Does anyone know of a reliable source of information on the twist rates in factory rifles? Do the firearms manufacturers have a standard that they use or do different makers use different twists?

This is a good start: Rifle Twist Recommendations from Shilen, Courtesy of Benchrest.com.

These are only recommendations, although fairly solid ones. You'll always find exceptions as twist rate vs. stabilization really depends on bullet length (as opposed to weight) and velocity.

- mike

Thank You MHO

Rick mentioned that buttons sometime wander and do not come with a precise twist. In the first place almost all factory barrels are hammer forged, and not buttoned. Button rifleing is considered very precise. A way that you can guarentee what you have in your guns is to take a cleaning rod with a fairly tight patch on a jag, Mark the rod with a piece of tape or a marking pen exactly one foot apart, push the rod into the barrel and count the number of complete revolutions between the two marks. Your twist rate can be figured by the amount of revalutions in the one foot space. Good luck, Bob

quote:

Originally posted by b beyer:
Rick mentioned that buttons sometime wander and do not come with a precise twist. In the first place almost all factory barrels are hammer forged, and not buttoned. Button rifleing is considered very precise. A way that you can guarentee what you have in your guns is to take a cleaning rod with a fairly tight patch on a jag, Mark the rod with a piece of tape or a marking pen exactly one foot apart, push the rod into the barrel and count the number of complete revolutions between the two marks. Your twist rate can be figured by the amount of revalutions in the one foot space. Good luck, Bob

Here is what I “actually†said...and I will stand by that statement which can be confirmed by any barrel maker. Note the terms “not always†and “sometimes.â€

“You should also be aware that an advertised twist rate is not always “exactly†as advertised either depending on the method used to rifle the bore. The tooling used in button rifling can sometimes slip just a bit and the actual twist can vary up to a half inch or so.“

Rick, I certainly did not to put down anything that you said, if it came across that way at all I am sorry. I mainly wanted to point out that just about all of the factory barrels today are hammer forged. Incidentally there was quite an interesting article in this last months issue of P.S. about hammer forging, the author thinking that they are a lot more accurate then they are given credit for. With the exception of a couple of makes,all of the custom barrels that I have used have been buttoned. These include Lilja, Hart, and Shilen,3 that I have a few each of. Another barrel that I have shot and had great luck with is Kreiger, although Kreiger is a cut rifleing proscess. I know of none of the barrels that are used in short range B.R. that are hammer forged. Again I apologize if I came across as if I was disagreeing with you, that was not my intention at all. As far as buttons slipping I can not cast an opinion on that as I just do not know. I do know that as I said, just about all the custom barrels used in what is probebly the most precise form of shooting, are button rifled. The exception to these are cut rifleing.

Rick is correct. But, it goes even farther than that. In button rifled barrels it is not at all uncommon for the twist rate to vary frequently throughout the length of the bore.

It has to do with a lot of things...the homogeneity of the steel being rifled, the specific shape of the button (opinions vary among barrelmakers as to which is best), the skill of the machine operator, the temperature of everything involved, whether there are "inclusions" in the barrel steel, reliability and consistency of the power source, and a bunch more.

For a while there was a company making its living by providing "scans" of barrel interiors, showing the actual twist every fraction of an inch therein. Some top custom makers used those scans to determine where to cut the barrel off for length...trying to do so just at the end of an extended length of barrel with little or no variation in twist.

Chris Dichter of PacNor used scans to learn how to eliminate much of the variation in twist from his barrels, when he first went into the barrel-making business. They reportedly played a large role in his determining what he thinks is the best shape for his rifling buttons...which may also vary in shape according to caliber and the twist rate desired.

Anyway, all of the factory and custom barrel makers today can pretty much make a barrel consistent enough you don't have to worry much about their barrels, when using them for hunting rifles, no matter what type of process they use to form their rifling.

quote:

Originally posted by b beyer:
Rick, I certainly did not to put down anything that you said, if it came across that way at all I am sorry. I mainly wanted to point out that just about all of the factory barrels today are hammer forged. Incidentally there was quite an interesting article in this last months issue of P.S. about hammer forging, the author thinking that they are a lot more accurate then they are given credit for. With the exception of a couple of makes,all of the custom barrels that I have used have been buttoned. These include Lilja, Hart, and Shilen,3 that I have a few each of. Another barrel that I have shot and had great luck with is Kreiger, although Kreiger is a cut rifleing proscess. I know of none of the barrels that are used in short range B.R. that are hammer forged. Again I apologize if I came across as if I was disagreeing with you, that was not my intention at all. As far as buttons slipping I can not cast an opinion on that as I just do not know. I do know that as I said, just about all the custom barrels used in what is probebly the most precise form of shooting, are button rifled. The exception to these are cut rifleing.

I wasn’t offended in any way. I also use custom made button-rifled barrels, but the guys I buy from (Shilen and Schneider) keep their tools sharp and monitor the rifling process like a mother hen watching her baby chics. Their barrels will shoot and clean right along with the best single point cut-rifled barrels out there.