Comments on: The Effect of Barrel Twist Rates on Muzzle Velocities

By: Ed Mahoney

Ed Mahoney — Sun, 11 Jun 2017 14:52:07 +0000

Hi
my question is how do you match a specific projectile to a specific twist to achieve the best accuracy.
Or what is the best velocity in what twist rate?
Thanks
Ed

By: Wim

Wim — Wed, 20 Jan 2016 13:27:49 +0000

I’m with Eric. I think the issue is the ability to run higher velocity in a slower twist, due to lower pressures and not whether the same ammo is substantially quicker or slower in a tighter twist.Still interesting I guess, but missing the real point of the twist selection discussion a bit I think.

By: Eric

Eric — Wed, 20 Jan 2016 07:03:34 +0000

I’d like to see them have a strain gauge on each barrel and seen if there were any significant pressure differences with starting at a fast twist vs starting at a slow twist.

By: Adam

Adam — Wed, 20 Jan 2016 01:40:33 +0000

Anytime Richard, I’m thinking of going 1-7 twist on my 7mm Rem Mag myself. Spin that 308 up and let her fly!

By: Richard

Richard — Tue, 19 Jan 2016 19:34:40 +0000

Thanks Adam. I’m not sure why it would not run 155 – 175s without problems. Make it a finished length of 24 inches and see how a fast twist runs. Can always cut it shorter then.

By: Guy

Guy — Tue, 19 Jan 2016 19:16:33 +0000

I known its a velocity study not a accuracy one but I cant help but wonder witch twist shot the best group.

By: Adam

Adam — Tue, 19 Jan 2016 04:53:58 +0000

You should be fine with a 1-8 twist 308 Win Richard. The only real concerns with a fast twist is if the jackets will hold up but that’s usually not an issue unless running thin jacketed projectiles at high velocities. And there will likely be a little more spin drift as well, but other than those two things, personally I see no real reason not to do it up… Just my take on that though, have a nice day!

By: Richard

Richard — Mon, 18 Jan 2016 19:45:24 +0000

I like Eddie’s comment. I have a 1/8 twist cal cal barrel in the cupboard that I do not know what to do with and keep on thinking a 308 Win would be good instead of another Whisper.

But contemporary window is that an 8 twist barrel will shake the core out and make the bullet more unstable at long ranges.

Velocity is one thing, but accuracy counts. Any comments on that aspect?

By: Guy

Guy — Mon, 18 Jan 2016 15:45:55 +0000

So velocity loss is basically a non event. Good to known.

By: Eddie in Texas

Eddie in Texas — Mon, 18 Jan 2016 15:11:36 +0000

Would rather see data on one bullet weight fired from different twist rates at different velocities to determine bullet frangiblity in ballistic jell. Example a 22 caliber 60 grain hollow point fired from a 1-14 twist at 3600 fps versus same bullet fired from a 1-9 twist at 2900 fps. Bullets react differently on live targets based on rotational speed more so that velocity. IMO….