.300 win mag barrel length and twist...

[coyotezapper]

Freebore and lead angle.

 

[DCAN]

Freebore and lead angle.

Thanks!

 

[ncwg2boatguy]

I run a 1-10 twist 26" and also have a 28". Both push 208 to 225gr bullets extremely well out to 1800 yds. But everyone's plans different. 1-10 ,26" is a great starting point. If you want to change in 2400rds swap barrels and give another twist a try .300wm is a jewel. Have fun .

 

[MagnumManiac]

I built and shoot a .308 Norma Magnum (very similar to .300WM) and I went with a 28" Bartlein 1-9 5R Sendero contour. I shoot the 208gr ELD-M with excellent accuracy. I chose the 9 twist over a 10 so I could shoot just about any 200+ grain bullet available. People say too fast twist won't shoot as well, but if you stay to heavy for caliber bullets you won't have a problem. Now with 150-180gr bullets the 1-9 is probably too much, but I believe it's smart to go with if you are building a magnum and intend to use heavy, high BC bullets.

I always say I would rather be a little over stabilized than be under stabilized and have to jump down to a ballistically inferior bullet. You can go too extreme with too fast of a twist and you'll potentially blow up bullets or distort them. A 9 twist in a .300 with heavy bullets is perfectly fine.

The 1:10" twist is fine for 230+gr bullets, the STANDARD twist in 30 cal is actually 1:12".

As to 'over stabilised', there is no such thing. A bullet is either stable or unstable in flight.
A bullet can be spun so fast that it is ripped apart by centrifrugal forces, but it is in fact stable prior to this.

Cheers.

 

[WildRose]

I,m thinking of a 180 gr .224 solid bullet in a 375 weatherby case, running a 1x5 twist and a 34" barrel for 3000 yard shooting as 4500 fps.

Make sure your life insurance is paid up before you pull the trigger on that hotrod.

 

[eastbank]

a little fun poked at the must have the newest, best do every thing crowd.

 

[SapperRIP]

A 1:9" is fine but when I rebarrel my 300wm I'll be looking to go 1:8" if possible so I can shoot the big solids like the 227gr Hammer Hunters (https://hammerbullets.com/product/308-cal-227g-hammer-hunter/), but with a 1:9" you can still shoot their 199gr and 214gr offerings.

I agree with going between 26-28" on length, especially if doing the carbon barrel over the steel.

Look at the new 2018 Browning Hells Canyon Long range

 

[SapperRIP]

http://www.bergerbullets.com/twist-rate-calculator/

If you want to do some calculations before going all the way in. I have a 1:10 twist on a 26" barrel and have great stability, but there are many factors so maybe this site can help. I would agree with most that 1:9 is probably the most optimal for an all around twist, and 26" is preferred.

 

[Aoudad shooter1975]

I'd do 24 in barrel--good compromise with gain and length and carry ability.

1-10 to 1-9 will shoot almost all bullet weights--my 300 norma has a 1-10 and has not trouble with 210 and 225 grain bullets--it wears a 24.5 in barrel

 

[Docx]

http://www.bergerbullets.com/twist-rate-calculator/

If you want to do some calculations before going all the way in. I have a 1:10 twist on a 26" barrel and have great stability, but there are many factors so maybe this site can help. I would agree with most that 1:9 is probably the most optimal for an all around twist, and 26" is preferred.

That link is gold!
Stay above 1.3 but use minimum twist for your bullet/ velocity to maintain ideal tractability

 

[WildRose]

It was - but spinning it too fast makes it stay angled nose up as it descends creating an awful angle of attack /yawl that is not aerodynamic so starts to tumble. What you want is a "gracefully thrown football" remember how the perfect spiral noses down as it heads into the receivers arms. But bullets are not football shaped - yet. And yes it is the newer science in extr long range shooting

Have you ever watched a plane land? A slight nose up angle on descent is the most stable of all.

 

[WildRose]

One thing to keep in mind is that if ever you might need or want to shoot non lead bullets you will need a faster twist rate than for lead core bullets of the same weight due to the exaggerated length of the mono's.

Where a 1:10 is adequte for a lead core 230gr the 200gr mono will at best be only marginally stabilized and the 210 will not be due to the 10% or so difference in the densities of lead and copper.

 

[Docx]

Have you ever watched a plane land? A slight nose up angle on descent is the most stable of all.

That's the point. Being over stable is nose up. Perhaps good for a guided aircraft. Not so good for a projectile accuracy. As they say. This isn't rocket science - it's harder. Projectile science. There is actually a decent thread on tractability on this site. Check it out. I am just a messenger. No expert

Oh and remember. No one hunts beyond supersonic. That's where all this crap comes to play. So prob irrelevant - but interesting. Enjoy
Ciao

 

[WildRose]

That's the point. Being over stable is nose up. Perhaps good for a guided aircraft. Not so good for a projectile accuracy. As they say. This isn't rocket science - it's harder. Projectile science. There is actually a decent thread on tractability on this site. Check it out. I am just a messenger. No expert

Oh and remember. No one hunts beyond supersonic. That's where all this crap comes to play. So prob irrelevant - but interesting. Enjoy
Ciao

You're only wrong on all counts here. As I said "slight nose up angle" and many of us here have and do hunt at ranges where the bullets are going transonic or subsonic.

An unstable bullet or marginally stable bullet will never be as accurate as a stable bullet the physics simply won't allow for it. It is when they become marginally stable that significant yaw develops which then has a negative impact on accuracy.