Saubier.com  



Go Back   Saubier.com > Saubier.com Forums > Small Caliber Discussion Board

Reply
 
Thread Tools Display Modes
  #11  
Old 09-07-2019, 03:14 PM
L.Sherm L.Sherm is offline
Senior Member
 
Join Date: Feb 2014
Location: Havre, Montana
Posts: 692
Default

Bill, my 9 twist shoots the 55's phenomenal at 3750.
Take this for what it's worth I know of guys who get about 300 rounds down a 8tw. Going at a out the same speed as mine start tearing up the 55's.
I believe a guy by the name of Terry over on small caliber shot a 4" group with a 9tw and 55's at 1000 in competition he post thecresult about a year or so ago.
Reply With Quote
  #12  
Old 09-07-2019, 03:26 PM
Bill K Bill K is offline
Senior Member
 
Join Date: Aug 2012
Location: N.E. Kommie Kalifornia
Posts: 6,304
Default

I will have to do some checking on that Sherm.. Maybe a 8 or 9 twist would work well, from what you show and say. I keep thinking about re-barreling one of my 22-250's to s 20. Check time coming. Bill K
Reply With Quote
  #13  
Old 09-07-2019, 04:00 PM
orkan orkan is offline
Member
 
Join Date: Jul 2019
Posts: 40
Default

I'm running 9 twist for the 55's as well. Works excellent.
Reply With Quote
  #14  
Old 09-07-2019, 04:05 PM
Jordan Jordan is offline
Senior Member
 
Join Date: Sep 2006
Location: Alturas, California
Posts: 586
Default .20 Cal Bergers....

Tim Gardner at Douglas (hope I have his name right) shoots a 9 twist in 1000 yard comp (I think) and it stabilizes fine. L. Sherm, what is your cartridge and barrel length please? 3750 fps is impressive.

Jordan
Reply With Quote
  #15  
Old 09-07-2019, 04:58 PM
L.Sherm L.Sherm is offline
Senior Member
 
Join Date: Feb 2014
Location: Havre, Montana
Posts: 692
Default

I'm running a 20 Nitro basically if you follow the BR world it's a 6 BRAI necked down to 20 cal. I did mine on a 28" inch tube but velocity wise it's no different than this first one I loaded for with a 24" barrel for a coyote hunter.
I ran Badger Bob's 46.5 up to 4050 just to see how fast I could get them. I stopped there I never did hit pressure or with the 55's either both just shot so well I just stopped.
Reply With Quote
  #16  
Old 09-07-2019, 05:48 PM
410gauge 410gauge is offline
Senior Member
 
Join Date: Jun 2013
Posts: 246
Talking

Well...here we go again...LOL! This subject with large case capacity 20 calibers has been discussed many times on this forum and others. As Sherm says the 55 gr Berger works very well in the 6mmBR cases (20BR, 20 Dasher, 20 Nitro) necked down to 20 caliber with the 1:9 twist. My current 20BR has a Bartlein 1:9 twist. It has right at 1500 rds through it. Very tired, but has still produced a slightly under (3) shot group at 100 yds of less than a 1/2" recently. I have a spare already built and ready to go, but have not installed it yet, as I'm trying to get all the goody I can get out of the old barrel first. I'm not the shot VolDoc is. My best with the 20BR on PD's has been right at 700 yds...but I have killed a few dogs now at slightly over a 1000 yds (confirmed by a long range shooter friend of mine through a spotting scope) with my 20-250 and the 55 gr Berger. Heaven forbid...but it's a 10-twist Kreiger! I have 400 rds through the 20-250 now, and it is still doing well for throat erosion. No bullet poofs either. Admittedly all of my shooting with the 10-twist Krieger has been above 4500' altitude, with most shooting above 6500' altitude. It is possible the B.C. is not as good with the 10-twist barrel as say a 7 or 8 twist barrel would be...but out in the field I can't tell it. The accuracy is there, and it still wacks a PD very well at long range. Slowing the bullet RPM down, seems to have helped. I've also slowed the speed down to about 3850 fps. If I'm able to get past the 600 round count with the 20-250...then to me the 10-twist has been worth installing. Like I've said before...will see! Just my .02 worth. 410gauge
Reply With Quote
  #17  
Old 09-07-2019, 06:22 PM
B23 B23 is offline
Senior Member
 
Join Date: May 2016
Posts: 781
Default

I talked to Berger about what twist rate to use when I was getting ready to order barrels from Krieger for my 20-250.

Berger bases their recommendations for twist rate on the bullet being shot from the slowest cartridge and at sea level elevation. For all practical purposes, it's very unlikely a 7tw would ever be required. Berger also told me they have fielded many calls from very unhappy users of these 55's because the bullets weren't surviving the launch to the target. IMO, that's something Berger can be faulted for because they recommended a 7tw and at 20BR or 20-250 speeds, these bullets will never make it to the target.

There has always been a lot of discussion about whether you need an 8tw or 9tw to shoot the 55's from these larger case capacity cartridges. As this thread has shown, there are plenty of people using a 9tw with great success. I spent a good amount of time talking to Berger about which twist to go with.
Per Berger, in order to get the full BC of the bullet, you need an 8tw. A 9tw may very easily shoot the 55's very well, but you won't get the maximum BC of the bullet. Again, these are Berger's words, not mine.

I also talked to Kevin Weaver a good amount. Kevin has built quite a few 20-250's. He recommended an 8tw as well, so I quickly ordered up two Krieger 8tw .20 cal barrels. These hot rod .20's aren't much for barrel life and waiting six months+ to get a barrel sucks so I ordered two barrels when I placed my order.

When I broke word Berger was discontinuing their 55's awhile back I stocked up pretty heavily so I don't really need to order any, but then again, when has "need" ever stopped me before.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 11:57 PM.


Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.