Bullet stability and spin as it relates to barrel length????

[Mike8623]

Got a question, I'm in the planning stages of a Winchester 1886 in 50-110 with the heavier bullet weights. I would like a shorter barrel though somewhere around 20 inches. Since the 50-110 seems to like a longer twist rate like 1X24 or so, I was wondering if the barrel was 20 inches how would it affect bullet stability does a bullet need make at least one complete turn to be effective or will it be stable enough without making that complete turn anyway I would appreciate all thoughts on this

[BAGTIC]

Should not make any difference. It is not the number of rotations that matter it is the rate of rotation and that is dependent on twist rate and not barrel length.

[Terry Murbach]

OKAY, STOP AND THINK HERE. A MUZZLELOADER HAS A 1IN60" TWIST AND THE BARRELS ARE NOWHERE NEAR 60" LONG. A S&W 2" SNUB 38 HAS 1 IN 18" TWIST. BOTH EXAMPLES WORK FINE. ONCE THE BULLET IS IN THE RIFLING IT TAKES ON THE REVOLUTIONS OF THAT BARRELS TWIST AND NEVER QUITS SPINNING AT THAT RATE FOR ALL PRACTICLE PURPOSES. THE VELOCITY HAS NOTING TO DO WITH IT AT ALL. IT'LL STILL BE TURNING AT THE RATE THAT BARREL GIVE IT IE: I IN 24" FOR YOUR EXAMPLE ALL THE WAY TO HECK AND GONE.

[Buck Elliott]

Barrel length has nothing to do with it. If you plan on using the "heavier" bullet weights, you'll probably want to go for a 20" twist (or even a little faster), as the 24" twist was designed for the 350-gr. bullet.

Remember, when the bullet is in flight, it's rpm, not revolutions per foot that stabilizes the bullet..

As Terry said, the bullets rotational velocity holds up almost undiminished over the flight of the slug, unlike it's linear velocity, which is rapidly shed, due to air resistance.

[Mike8623]

I was thinking of a 450 grain bullet, what twist rate would you think appropriate, is there a formula for twist rates?

[msmith1228]

Yes, the greenhill formula.

[Mike8623]

Well I'm confused now............the bullets I plan on using are the barnes .510 diam, 450 grain with a length of .925, according to the greenhill formula, If I'm getting it right the twist rate should be somewhere around 1 in 42. I thought you neede a faster twist with a larger grain bullet is it the other way around????????????? Can someone straighten me out

[Chas.]

If you'll notice, the greenhill formula ignores bullet weight. It's only concerned with bullet length. I'm not defending the formula, just providing some enlightenment.

[Bullard4075]

The shorter the bullet the slower it needs to spin for stability.
Muzzleloader roundball twist rates can be on the order of 1 in 66.

[Mike8623]

Well Guys let me ask this question:

What twist rate would you pick for a Winchester 1886 50 cal. 450 grain bullet?

[Buck Elliott]

1:20"

[Mike Rintoul]

I think Mr. Murbach was first to cite this right and the Greenhill Formula was also mentioned. I will add something I always say that I have learned through experience - A bullet is going to do what a bullet is going to do!

[Grizz]

Well Guys let me ask this question:

What twist rate would you pick for a Winchester 1886 50 cal. 450 grain bullet?

Mike, I'd pick 1:20

Grizz

[Thunder50]

I think JES reboring does 1-22" for his 50 cal rebore. I can shoot a 750gr just fine with my 50ak