I'm in the process of working up loads for a Winchester Mod.100 (I have another thread posted specifically for that) and I picked up some more nice pills from a great fellow CGNer (thanks Rob). I bought some 150 gr. Nosler Accubond and some 155 gr. Berger bullets from him. I have reload data from the Nosler website, but Berger is thin on information. According to the box, these 155's are suitable for both target and hunting. They're a boat tail hollow point bullet and on the box it specifically states for 1-14 rate of twist or higher. I have 2 rifles chambered in .308; an older Ruger M77 HBar which has been a tack-driver with my handloads, and my Mod.100. I believe that they're both 1-12 twist rate. As I understand it, would that mean that I can't expect acceptable accuracy out of my rifles with the Berger bullets or does it just mean that I won't get the maximum performance out of them? As an aside, I do have a pet peeve with Sierra and Berger when it comes to reloading information. Speer and Nosler both give free reloading information on their web sites. With Berger and Sierra, you have to buy their reloading manuals.
Berger bullets & twist rate question
- Thread starter LawrenceN
- Start date
Depending on powder go to imrpowder.com and use their online load data. A 155 is a 155 is a 155 (with the exception of the solid copper stuff)
Use any normal 155 data and work up accordingly.
Berger is thin on loading data. But I believe they have more info, if you email them they will give it to you
Use any normal 155 data and work up accordingly.
Berger is thin on loading data. But I believe they have more info, if you email them they will give it to you
Actually I think Berger sets the standard for providing information about their bullets. An example is the twist rate on the box. What twist does Nosler say their bullet needs? Or Sierra? First Berger provides a Quick Reference Data sheet of all their current bullets. It includes a G7 Ballistic Coefficient for boat tails, which most other manufacturers do not provide. And they provide a Form Factor for their bullets which allows you to quickly select the bullets with the best long distance trajectory. Those are the ones highlighted in green on the chart. And they provide an on line calculator to determine twist rate, both for stability and maintaining BC down range. You can input your twist rate and see how that stacks up given your muzzle velocity and elevation. Here are the links:
Quick Reference Sheet
Form Factor
Twist Calculator
And if you want to check required twist on other bullets like Sierra, Speer, Nosler based on dimensions you can use this calculator. Good luck finding the required dimensions from those guys though...
Kolbe Twist Rate Calculator
You can find a ton of information on the .308 at the Accurate Shooter Cartridge Guide page. There is even Sierra's Load Map free to download:
Sierra .308 Load Map
With Berger, you can e-mail them for specific caliber and bullet load data. Walt Berger, the original owner of Berger, used to respond personally. He is still there, so perhaps he is still doing it...
