24 January 2025, 19:26
Paul K9.3X62 twist rate
What would be the best twist rate for a new 9.3X62 barrel?
Paul
24 January 2025, 19:29
dpcdI use one in 12, and I only use Douglas barrels, and I make them to the 1930 Oberndorf countour.
24 January 2025, 21:15
PuddleThere's a twist rate calculator out there somewhere, I think it's called Greenhill?. In any case I've come across 1:14 and 1:12, and mine is a 1:10. Dunno why my factory barrel is a 1:10, best I can figure is for the 300+ grain bullets...
25 January 2025, 23:21
eagle27quote:
Originally posted by Puddle:
There's a twist rate calculator out there somewhere, I think it's called Greenhill?. In any case I've come across 1:14 and 1:12, and mine is a 1:10. Dunno why my factory barrel is a 1:10, best I can figure is for the 300+ grain bullets...
Greenhills Formula;
T=150xD/R
T=twist rate in inches (inches per one revolution)
D=bullet diameter in inches
R=ratio bullet length to diameter (bullet length divided by diameter)
150=constant, works well for velocities 1500fps or greater, can be changed to 180 for velocities >2800fps with good results.
12 February 2025, 04:15
AtkinsonI have used both the 1x12 and 1x14. in which case I could not tell any difference.
I could not find a 1x10, but that was about 10 or so years ago and the 1x12 and 1x14 worked wo well i never pursued it.