30Cal 1 in 18" Twist. What would you use these for?

[Four Fingers of Death]

Allan Swan, an Australian barrelmaker list this twist as an option. I have never struck a twist slower than 1 in 14 1/2" previously.

Light boolit / boolit usage? Any ideas?

http://www.allanswangunsmithing.com/barrels

[B R Shooter]

The 30BR started a whole new aspect to benchrest shooting. Using bullets ranging from 110 to 125 grains, barrels used are typically either 17 or 18 twist. They shoot exceptionally well. Some have tried as slow as 19, and do OK in warm weather, but that is on the edge of unstable. It is not limited to the 30BR though, if you want to shoot light bullets, you could use it in any 30 caliber.

[Stephen Cohen]

Alan is just up the road from me and does my work. I was talking to him last year about some slow twist barrels for cast.

[Four Fingers of Death]

Soup can boolits!

[swheeler]

4Fingers; that barrel should stabilize any boolit of .9" long(approx 150gr) once you reach 2400 fps

[Four Fingers of Death]

Thanks for the info. A pretty narrow range of application.

[MT Chambers]

As B R said....I think it is only useful for the .30 br. when shooting for score with 125 gr. J-word bullets, my .30 BR is only used for cast and has a 1-12" twist.

[Four Fingers of Death]

The 1 in 12" is a better choice for just about anything I'm thinking.

[Larry Gibson]

I would give the 18" twist a try but would use a case with larger capacity that the 30 BR. I'm looking at a 16" twist in 30x57 right now. Some think that the slower twist "limits" your bullet options. If you are a one rifle shooter they might have a point. However I "think" you've several rifles of .30/.31 cal that you shoot 170 - 200+ in already(?) Thus building one with the 18" twist for cast bullets of 150 - 160 gr with the idea of pushing them to 2700 - 3000 fps would be a possibility if one is interested in such. The RPM of such bullets is well below the threshold in the 18" twist. Such cast bullets as the LBT and 311466 are good choices. One then also has an excellent barrel twist for the lighter cast bullets such as the "soup can" mentioned".

BTW; a 14" twist in .308W will stabilize bullets upwards of 200 gr quite well, contrary to some opinions. I've been shooting several cast bullets (the LBT, the 311466, the 311465 and the MP 311-180) at 2400 - 2750 fps with excellent accuracy. Any of the readily available twist calculators will show which bullets will be stabilized at what velocities. Keeping the RPM down sure makes shooting cast bullets at higher velocity with accuracy a whole lot easier.

Larry Gibson

[Four Fingers of Death]

Good point Larry, I have a few old target 308s which have 1 in 14 1/2" twist barrels (originally built for the 147Gn Milsurp ammo). These would be fine cast boolit rifles I am thinking.

The 1 in 18" 30 cal barrels would work well with Loverin and 'stumpy' boolits I think.

[mikeym1a]

I found this both interesting and informative. More holes in my knowledge base filled.

[Four Fingers of Death]

Until I saw Allan's barrel page (I have looked at it numerous times, but never noticed them), I didn't realise that this twist was made. I have ended up with two 338WM Ruger No1s and am thinking of rebarrelling one, possibly in 270Win or 240WM