6.5 SAUM help please

Jerry M

Well-Known Member
Joined
Aug 20, 2006
Messages
692
Location
Glen Burnie MD
Berger Twist Rate Stability Calculator show marginal with 140 VLD and 8.5 twist. As stated above: try another bullet.

Good luck

Jerry
 

JD250

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Joined
Sep 17, 2012
Messages
104
Location
Central california
Berger Twist Rate Stability Calculator show marginal with 140 VLD and 8.5 twist. As stated above: try another bullet.

Good luck

Jerry
I know of two guys that shoot the 140 out of their saums with 8.5 and they shoot lights out that’s the reason I chose 8.5 I’m gunna exhaust my options with the bergers before I switch to an eld or something else.
 

Unclenick

New Member
Joined
Jun 6, 2018
Messages
4
Location
Ohio
The Berger range of "marginal" is wider than any other I have seen. I expect it is because they are trying to allow for people to go into colder conditions, or maybe for some lots of bullets to be longer than average. But several authorities from Harold Vaughn to Don Miller put stability factors of 1.4 to 1.5 as best for benchrest accurracy, while Berger is calling them marginal. I would have to ask to learn what their reasoning is. A Sierra tech told me long ago that gyroscopic stability factors of 1.3 to 3.0 are best for hunting accuracy and 1.4 to 1.7 was best for match accuracy.

Today you can get away with higher numbers for match shooting than you once could because bullets are made better and with more perfectly uniform mass distribution. Berger may be counting on that, but again, I'd have to ask. But check the calculator on their site or at the JBM Ballistics site or at Geoffrey Kolbe's site for a somewhat more comprehensive approach based on McGyro. Use your velocity and your atmospheric conditions and measure and use the length of the longest bullets in your box.
 

JD250

Well-Known Member
Joined
Sep 17, 2012
Messages
104
Location
Central california
So I loaded up and shot what berger recommends for their year for seating depth and my best group was touching the lands. 5 shots about 1”-1.25” with 60.2 gn h1000 at very consistent through the chrono at 2976-2982 I’m just going to run with that load for my hunt next week. I now have 121 down the tube I’m going to load up 50-60 of that load and head to the big range here and put it on paper out to 300 and shoot steel out to 750 and see if maybe things tighten up out there at further distances and just see what happens and get a feel for how far I can confidentially shoot at an animal with it the way it is then when I get back I’ll change things up with different bullets and powders and hopefully get this thing shooting to it’s true potential.
 
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