Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Rifles, Bullets, Barrels & Ballistics

Rifles, Bullets, Barrels & Ballistics Applied Ballistics


Reply

Twist rate 8.5 or 9 "

 
LinkBack Thread Tools Display Modes
  #1  
Old 09-12-2010, 07:52 PM
Platinum Member
 
Join Date: Apr 2004
Location: Reno Nevada
Posts: 1,522
Twist rate 8.5 or 9 "

Building a 7mm wsm I want to shoot 140gr to Berger 180 Gr VLD Berger says 9" twist will work with their 180 gr VLD. But other shooters use 8.5 " What difference does .5 make in that bullets flight ?
__________________
How does it profit a man if he gains the whole world but loses his soul?
Reply With Quote
  #2  
Old 09-12-2010, 08:12 PM
Gold Member
 
Join Date: Jan 2007
Location: Fairfax County, Va
Posts: 683
Re: Twist rate 8.5 or 9 "

My 7mm WSM has a 9 twist and shoots 180 Berger's just fine. The 8.5 will cost you a few FPS and will be harder on the bullets.
Dave
__________________
"How a politician stands on the Second Amendment tells you how he or she views you as an individual... as a trustworthy and productive citizen, or as part of an unruly crowd that needs to be lorded, controlled, supervised, and taken care of."
--Rep. Suzanna Gratia Hupp (TX)
Reply With Quote
  #3  
Old 09-13-2010, 11:30 AM
Platinum Member
 
Join Date: Dec 2008
Location: Northern Id.
Posts: 3,441
Re: Twist rate 8.5 or 9 "

I would agree that a 9 twist is adequate for most shooting. I you were going to shoot at extreme ranges and use the 180's, you might want the 8 1/2 to stabilize the bullet better. This probably wouldn't be necessary at under 1000 yds.....Rich
Reply With Quote
  #4  
Old 09-13-2010, 11:53 AM
Platinum Member
 
Join Date: Apr 2004
Location: Reno Nevada
Posts: 1,522
Re: Twist rate 8.5 or 9 "

I won't be making any 1000 yd shots on game. My rifle was a Mod 70 Classic in 270 WSM with a Factory bbl that threw bullets once the bbl was hot. ( 3 shots and bbl was hot) I'm now having a Krieger 9"twist 26" #4 contour chambered in 7mmWSM installed. Rifle would of been ok for a once a season deer rifle. But I shoot all the time.
__________________
How does it profit a man if he gains the whole world but loses his soul?
Reply With Quote
  #5  
Old 09-13-2010, 12:22 PM
Platinum Member
 
Join Date: Feb 2009
Location: Sedalia, MO
Posts: 1,253
Re: Twist rate 8.5 or 9 "

Ironworker,

The difference between a 1x9" and a 1x8.5" is virtually (and may be, literally) non-existent, depending on the method of manufacture. It's not at all uncommon for buttoned barrels to vary by a half inch either way, so that 9" twist could very well be an 8.5" in reality, or even a 9.5". Cut rifled barrels tend to be a good bit more consistent in this regard, but both methods can produce good barrels, and I'm not knockign the buttoned variety. My point is, given a minor difference like this, I'd tend to go with the faster. A bit of extra spin will very rarely cause you any problem, while not enough will be a major pain in the arse every time.

Kevin Thomas
Lapua USA
Reply With Quote
  #6  
Old 09-13-2010, 07:48 PM
Silver Member
 
Join Date: Oct 2007
Posts: 157
Re: Twist rate 8.5 or 9 "

I would go with the 9 twist. Not as hard on the bullets, a little less pressure, and still is plenty to get a 180 brger to fly well.

aroshtr
Reply With Quote
  #7  
Old 09-13-2010, 07:56 PM
Platinum Member
 
Join Date: Apr 2004
Location: Reno Nevada
Posts: 1,522
Re: Twist rate 8.5 or 9 "

Barrel has been ordered. Its brux 9" twist cut rifled bbl. Brux had the shortest lead time of all the barrel makers
__________________
How does it profit a man if he gains the whole world but loses his soul?
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Twist rate 8.5 or 9 "
Thread Thread Starter Forum Replies Last Post
What are "break velocity" and "retard. coeffic. rate"? Monkeyleg Rifles, Bullets, Barrels & Ballistics 1 01-02-2011 12:14 AM
Ruger M77 Flatbolt 22" .243 Twist Rate? TnTom Rifles, Bullets, Barrels & Ballistics 2 11-18-2010 05:16 PM
Twist Rate??? AtownBcat Rifles, Bullets, Barrels & Ballistics 19 05-13-2009 04:05 PM
270 twist rate jmason Rifles, Bullets, Barrels & Ballistics 6 08-05-2008 01:13 AM


All times are GMT -5. The time now is 11:38 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC