ml williford
Well-Known Member
Hello, I'm in need of advice. I'm going to have a 257 magnum built. It will be 26 inch proof barrel carbon fiber. Will be shooting 100 grain bullet. Plus or minus 10 grains. What is the best twist rate for this?
Twist rate
- Thread starter ml williford
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Jakeweb09
Well-Known Member
Probably 10 twist unless those bullets are copper. If you have any interest in shooting 130 classgo with 7.5!
I'll go first. (Second) Your fastest (minimum required) twist might be for 110 grain copper bullet. Hammer hunter specifies a min twist of 8.25. Your slowest twist would probably be a 90 grain lead core. I'll bet you could go down to 10 twist but I'd aim for at least 9 twist maybe faster.
ml williford
Well-Known Member
No sir, nothing heavier. How does copper change things?
ml williford
Well-Known Member
Thank you sir.
Jakeweb09
Well-Known Member
Copper bullets of the same weight require a much faster twist as they're longer then lead. So look at the bullet you're wanting to shoot as David said above, 110 hammer hunter specifies 8.25 twist minimum! So if planning to shoot copper in that range I personally would be going 7.5 twist
Alex Wheeler may still have a 25cal.
Barrel for sale, 7.7 to 7.5 twist.
Barrel for sale, 7.7 to 7.5 twist.
download my app and it will give you Gyroscopic stability and RPMS
www.eagleballistics.com
www.eagleballistics.com
Phil Rizzo
Well-Known Member
1-9" is good for 110-115gr Nosler's started out at 3400-3500.
Monos need 7-7.5 I'd think.
Monos need 7-7.5 I'd think.
sable tireur
Well-Known Member
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- Oct 8, 2010
- Messages
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The traditional factory twist rate for the .257 rifle cartridges has been 1:10" for a long time. This is due to the prevalence of the shorter cup and core (lead) bullets.
The current trend though has moved towards the longer, sleeker VLD bullets and the solids which are significantly longer than the lead core copper jacketed bullets. Longer bullets change the required twist rate to the 1:9" or even faster, some running as fast as 1:8.25" for copper solids in the 100 grain range. The discontinued 100 gr. Berger Classic Hunter needs a 1:9" for proper stability.
In many cases simply stating a weight isn't as helpful as the bullet construction and the length of the bullet chosen. It's sometimes easier to run some of your data through the Berger Stability Calculator to do a 'what if' for the suggested twist rate before making a commitment to any bullet in particular.
https://bergerbullets.com/twist-rate-calculator/
JBM Bullet Length List (not updated)
https://jbmballistics.com/ballistics/lengths/lengths.shtml
Enjoy the process!
The current trend though has moved towards the longer, sleeker VLD bullets and the solids which are significantly longer than the lead core copper jacketed bullets. Longer bullets change the required twist rate to the 1:9" or even faster, some running as fast as 1:8.25" for copper solids in the 100 grain range. The discontinued 100 gr. Berger Classic Hunter needs a 1:9" for proper stability.
In many cases simply stating a weight isn't as helpful as the bullet construction and the length of the bullet chosen. It's sometimes easier to run some of your data through the Berger Stability Calculator to do a 'what if' for the suggested twist rate before making a commitment to any bullet in particular.
https://bergerbullets.com/twist-rate-calculator/
JBM Bullet Length List (not updated)
https://jbmballistics.com/ballistics/lengths/lengths.shtml
Enjoy the process!
Gary in MD
Well-Known Member
10 twist to shoot traditional bullets up to about 120 grains.
A 100 grain bullet out of the 257 Mag @ 3500 - 3700 has been destroying stuff for a long time.
RockyMtnMT
Official LRH Sponsor
As a general rule faster twist is better. Higher stability will help with terminal performance keeping the bullet point on after impact for more consistent deformation and straight line penetration. Some thin jacketed lead core bullets might struggle with the fast twist. Quality hunting bullets should be fine. I personally look at 7" twist for 25 cal. I wouldn't go slower than 7.5" twist.
That said you can get by with the old standard 10" twist, it just handicaps you a bit.
That said you can get by with the old standard 10" twist, it just handicaps you a bit.
.257 WBY? Mine is 1:7" built for the heavies; 131 BJ, 133/135 Berger, 134 Hornady ELD-M, 145 Black Hole, 163 Chinchaga, etc., but have no issues shooting 100-130 C&C bullets. Good luck!
ml williford
Well-Known Member
Thank you for this info sir.
