223 twist rate for 90 g bullet

[Dave Zander]

223 bolt gun 30” barrel with 85.5/90 g bullets. Anyone have any luck with 6.5 twist for long range shooting ?
Bullet jackets coming apart or accuracy issues?

 

[DukeDuke]

I shoot 88, 90 and 95 out of a 26" Krieger 6.5 twist at about 2750 fps with 0 issues.

 

[Dave Zander]

Thanks.

 

[Dave Zander]

Who makes the 95’s?

 

[Walt Krafft]

Sierra

 

[Ned Ludd]

223 bolt gun 30” barrel with 85.5/90 g bullets. Anyone have any luck with 6.5 twist for long range shooting ?
Bullet jackets coming apart or accuracy issues?

Use a 0.219"/0.224" bore/groove configuration barrel. There are a number of critical factors such as barrel length, land/groove configuration, bullet velocity, bullet RPM, etc., but jacket failure mostly boils down to friction. When using a 30" 0.218"/0.224" bore/groove configuration, the odds of having jacket failure will increase markedly when using twist rates of less than 7.0. Velocities greater than about 2825 fps or so, barrel lengths of 30" or longer, and twist rates faster than 7.0, can all make the risk of jacket failure higher in a 0.218" bore barrel. However, switching to a 0.219" bore barrel will largely make the other critical factors disappear, and a 6.5-twist rate should no longer be an issue.

If you already have (are using) a 0.218" bore barrel, stick with a 7.0-twist and keep the velocity below 2800m fps and that should minimize the chances of jacket failures. I have had issues in the past with jacket failures out of a 0.218"/0.224" 30" 6.8-twist 5R barrel using the Berger 90 VLD and the Hornady 88 ELDM bullets. That barrel did not cause jacket failures with Sierra bullets, which apparently have thicker/tougher jackets.

 

[Evan]

In Colorado at 5000ft elevation, an 8 twist works. I’ve not taken it lower. A 7.7 twist worked at Deep Creek (~3000ft).

My 7 twist Bartlein would blow up bullets all the time. I would be really worried about a 6.5 twist.

 

[dcali]

7" with a .219 bore is what you want. Barrels are already hard on 90s. You don't want to spin them too fast or you risk blowups.

 

[dusterdave173]

I have a new 7 twist Hawk hill barrel with about .170 freebore It Loves 85.5 Bergers I have not tested the 90's and may not

 

[ltebiker]

We have shot 6.25 and 6.5 twist with 80-90gr no issues and great accuracy with 32” barrels… I do shoot moly pills. Good Luck

Lucas