twist rate?

[BradY]

Can anyone tell me if a 90gr SMK or berger VLD will stabilise in a standard 22BR with a 7 twist 28' barrel? Berger says the VLD needs a 7 twist bit sierra says thier SMK needs a 6.5 twist. Surely the VLD would be longer than the SMK?

 

[rcw3]

They'll both stabilize in a true 1'7' twist. I have shot them both out of 7' twist barrels and had no stability issues with either of them in a couple different 7' twist barrels. Speaking to Bryan Litz at Berger Bullets on this he indicated that the Berger 90's actually were o.k. with a little looser than a 7' twist, so the 7' twist recommendation actually has a little margin for error built into it.

Robert Whitley

 

[BradY]

Thanks Robert, I suppose its no real drama as im going to get the 7 twist anyway, just that nowhere in australia sells you 15 packs of bullets so you can try them out before you spend the significant amount for a full box. I have decided to do another BRX to push them a whisker faster so that may help me out a bit too.

 

[Obtunded]

In a 22BR no problem. With the low velocities you'd get from a .223, the 7 twist would be important.

The problem with Berger et al, is their twist reccommendations are not associated with velocities. A 220 Middlestead and a .223 Remington have very different requirements for the same length/weight of bullet.

 

[BradY]

Another shooter at the range today actually said a 7 twist is a waste in the 22BR and may break up my projectiles. He said an 8 twist would do it, but i really dont believe it. Especially with us shooting so close to sea level.

 

[chino1969]

Another shooter at the range today actually said a 7 twist is a waste in the 22BR and may break up my projectiles. He said an 8 twist would do it, but i really dont believe it. Especially with us shooting so close to sea level.

Brady,
Until you try the bullet in your own rifle, you'll never know for sure.

Lou Baccino