Twist rate: How do I find my twist rate of a rifle?

[Ivantherussian03]

How do I find my twist rate of a rifle?


I have a k31, K98, and M96. I want to learn more about it?

[mooman76]

Take your cleaning rod with a cleaning jag and a good tight patch. Mark the cleaning rod and the muzzel of you gun with something and push the rod in until it makes one full revolution. If it takes 18" of the cleaning rod to make a full turn then it is 1/18 and so on!

[Ivantherussian03]

1/13 is what I measured on my K31 does that sound right?
1/12 is what I measured on my Remington 721.


How does this knowledge help me make better loads?:roll:

[wiljen]

Castpics also has a twist rate table that contains most popular calibers and rifles including some of the milsrups. It is hiding under the Research and Data section on http://www.castpics.net

It is also worth noting that with commercial models that came in more than 1 chambering, the twists will vary with chambering as well. So to answer the question regarding the 721 you would need to include that information.

[Maven]

Ivan, According to the Swiss Rifles site, the K-31's twist rate is 1:10.63. Here's the link:

http://www.swissrifles.com

[405]

Like mooman, the best is the knowledge to check your own. Doesn't take two minutes and ANY rifle can be checked. Then just make a note on your load data log for that rifle- everyone should be keeping a data log:coffee:- Right at the top of the first sheet on my log for each gun/cartridge is the twist rate, chamber length/throat length and slugged groove dimensions. Then if the gun is not shot or loaded for, for a while I can go back to the log sheet and find the start data, best loads, best bullet dimensions, seating depths, etc., etc. Relying on memory alone isn't too good most of the time.

[mooman76]

I have a list of all my guns on my computer. You'd be surprized how few people even have a list and if there guns were stolen heaven forbid they wouldn't even have the serial numbers. But anyway I added a few things some time ago (easy on the computer) when I started slugging the barrels. I also added a block for twist rate. One of these days I will check all of them!

[Ivantherussian03]

Thanks guys. I just made a list of serial numbers, make, and model of my guns. A log data book is a smart idea, I keep one for the maintainece of my house and truck, and will start one for my guns as I play with them.

[Nelsdou44]

Mooman is right on about using the tight patch on a cleaning rod. The only thing I can add by my experience to "measure" a number of times and average the readings.

Nels

[Ivantherussian03]

there is a wealth of knowledge on this board!

thank you all

[fourarmed]

If the jag is not a good tight fit in the rod, the best way to measure the twist on a rifle with right-hand twist is to push the rod, jag, and tight patch into the bore farther than one turn, screw the rod firmly onto the jag, then put a piece of masking tape on the rod at the muzzle, and mark it at the top. Now pull it OUT of the barrel until it rotates one turn and measure from the tape to the muzzle.

If the rifle has left-hand twist, then it works best to measure it pushing the rod into the barrel. This way, you don't have to worry about the jag unscrewing from the rod and messing up the measurement.

Edited to add: the jag can still turn in the patch and foul up your measurement.

[sturf]

the 98 is 1 in 9 1/4. the 96 is 1 in 7 1/2.