Barrel twist rates?

[muffler man]

I was wondering if anyone knows of a simple chart for barrel twist rates? Something that compares bullet weight to barrel twist that can be downloaded and kept for future reference. Thanks, Joe

[knight0334]

It is bullet length that is the factor, not so much bullet weight. Velocity is the other factor.

You can have lighter weight bullets that are longer than heavier ones, and they would require the faster twist rate. Even bullets of the same weight could be an issue. ...One company's 62gr bullet might be shorter than another company's 62gr bullet. One might have a rounded nose, the other a spitzer profile. Or one might be all copper, the other lead with copper jacket.

Velocity plays a major part in the required twist rate too.


Here is a calculator if you have the known facts; velocity, diameter, length: http://kwk.us/twist.html Leave the "bullet SG" at 10.9 for jacketed lead bullets.


Here is a chart per bullet weight - but it would be flawed due to the reasons I describe above. http://www.varminthunters.com/tech/barreltwist.html

[aubie515]

Here is a good link from Lilja.

http://www.riflebarrels.com/products...wist_rates.htm

Just keep in mind that barrels from different companies may behave differently.

Some folks say that their 1:9 twist will stabilize a 69gr .224 bullet, while others will require a 1:8...etc etc.

[muffler man]

There is a lot more to this than meets the eye. I was just trying to get a better understanding before reloading my next round. I thank you for the charts. Now I'm off to do some studying. Joe