What’s the point in slow twist?

[Dialing Long Distance]

I see a lot of rifle manufacturers with offerings of magnum calibers in slow twist rates. (for example Browning among many others) chambered in 7 mm Remington Magnum with a twist of 1:9, or 1:9.5. Why would rifle manufacturers have their barrels twisted like this, aren't most people are looking for 1:8 twist to stabilize heavier bullets? I have never heard of a light bullet being "over stabilized" (let's say shooting a 140 grain 7mm through a 7rum) in a fast twist barrel, but I suppose it could happen(?)

We've all seen some manufactures make the mistake of putting slow twist barrels in certain calibers (1:9 for the 260 Remington comes to mind) thus rendering the calibers a disappointment. To me it would just make more sense to go with a faster twist, why don't they?

 

[MudRunner2005]

I see a lot of rifle manufacturers with offerings of magnum calibers in slow twist rates. (for example Browning among many others) chambered in 7 mm Remington Magnum with a twist of 1:9, or 1:9.5. Why would rifle manufacturers have their barrels twisted like this, aren't most people are looking for 1:8 twist to stabilize heavier bullets? I have never heard of a light bullet being "over stabilized" (let's say shooting a 140 grain 7mm through a 7rum) in a fast twist barrel, but I suppose it could happen(?)

We've all seen some manufactures make the mistake of putting slow twist barrels in certain calibers (1:9 for the 260 Remington comes to mind) thus rendering the calibers a disappointment. To me it would just make more sense to go with a faster twist, why don't they?

Because for 40+ years, nobody offered much heavier than a 175 grain low BC roundnose or soft point bullet for the 7mmRM in their factory loaded ammunition. And the minimum twist for those is 1:9.5". They are too cheap to update their tooling to accommodate modern twist rates for older cartridges. It's a **** shame, too...Because they think they're saving money, when in reality, they're losing sales, so they're losing a LOT more money than they're actually saving.

If Remington would listen to its customers, I bet you they could be the best selling rifle company on the market once again. But they need somebody to make those choices to progress them into the "now", instead of dwelling on what worked 20 years ago. The game (precision and distance) has changed, the bullets have changed, and gun needs have changed. Companies that don't progress with "the game" get left behind.

If Remington would offer 5R rifled 1:8 twist 7mm barrels in all their cartridges, their 7mm cartridges sales would be through the roof!

 

[Dialing Long Distance]

That makes sense, I see a lot of gourmet rifle builders using faster twist rates accommodating the heavier, high BC bullets, I would think mainstream gun manufacturers would do the same thing. With the revenue they do bring in, you would think they would want to spend some of their money on keeping up with the times. I would think that would be just good business practice.

 

[mobenzowner]

You can spin certain bullets too fast. They can actually come apart in flight. It's a non issue for most of us shooting mid to heavy for caliber, but some folks actually shoot light for caliber bullets.

 

[Barrelnut]

Berger has a FAQ on it.
http://www.bergerbullets.com/wp_super_faq/why-do-you-recommend-the-slowest-twist/

 

[Dialing Long Distance]

I am curious, is there an argument for spinning a bullet too fast? Like my Remington model 700 chambered in 243, I believe that has a twist of 1:9.5, I have found that burger 105gr VLD's do not shoot out of this rifle. I understand those bullets were never even thought of when the rifle was manufactured, I understand it was manufactured with bullets closer to 80 grains of weight in mind. Does a 1:8 twist over stabilize a bullet that is light in weight like though? Is there such a thing as "over stabilizing"?

 

[Dialing Long Distance]

You can spin certain bullets too fast. They can actually come apart in flight. It's a non issue for most of us shooting mid to heavy for caliber, but some folks actually shoot light for caliber bullets.

You posted this as I was typing my reply. I did not know bullets could actually come apart like that.

 

[MudRunner2005]

You can spin certain bullets too fast. They can actually come apart in flight. It's a non issue for most of us shooting mid to heavy for caliber, but some folks actually shoot light for caliber bullets.

That takes ALOT of RPM's... Much more than going down an inch or so in twist rate, unless you're already running a ridiculously tight twist, and trying to push the bullet beyond it's maximum RPM range. Under most normal circumstances, this type of phenomenon doesn't happen.

 

[Barrelnut]

Exploding bullets is not the only reason check out the Berger FAQ ^^^

 

[Cow Town Bill]

I am curious, is there an argument for spinning a bullet too fast? Like my Remington model 700 chambered in 243, I believe that has a twist of 1:9.5, I have found that burger 105gr VLD's do not shoot out of this rifle. I understand those bullets were never even thought of when the rifle was manufactured, I understand it was manufactured with bullets closer to 80 grains of weight in mind. Does a 1:8 twist over stabilize a bullet that is light in weight like though? Is there such a thing as "over stabilizing"?

For the 105's you should have an 8 twist barrel for best accuracy. The 8 twist can indeed over stabilize the lighter bullets with thin jackets---I've had 87 Vmax bullets that either blew up or fired off in some weird trajectory with my 6 SLR (similar to a 243 Win)
The Berger twist calculator should be used with some caution with light thin jacketed bullets---perhaps the calculator is intended for their bullets only.

 

[Garycrow]

A faster than needed twist can exaggerate imperfections in the bullet's balance and cause less accuracy than if the twist were exactly matched to the bullet's length. That's the reason the benchrest guys that are seeking the absolute max short range accuracy run really slow twists. That's mostly a non factor today because today's bullets are so good and there aren't really any balance inconsistencies to cause problems. The idea that too fast a twist is going to cause accuracy problems is really more theoretical than reality today and I'd much rather over twist than under twist, any accuracy lost to faster than needed twist rates is going to be so small that it would be almost impossible to quantify.

A too fast twist can spin bullets apart though. I have a 20 practical that I had built with a 1-8 twist that'll spin apart 39 gr. sierra blitzkings about half the time. The two options I had for twist were 1-11 and 1-8 with the barrels I had available at the time. I really wanted a 1-10 but was planning to shoot 40 gr. bullets and the twist rate calculator showed 11 twist to be marginal so I went with 8. The thin jacketed sierra's will come apart so I run 40 gr. VMax's and Ballistic tips which have thicker jackets and don't come apart. Any decent hunting bullet in a hunting caliber will be tough enough to where that won't be a problem.

 

[Predator 22]

I run a 1:14 twist 22-250ackley for prairie dogs and predators. 50gr z-max at 4000' sec sends pd's into low earth orbit and blows big holes in coyotes if I don't hit a shoulder. I shot a coyote last winter just under 100 yards behind the shoulder and blew a hole out the other side big enough to put both my fists in. The blood "trail" from him spinning in a circle was amazing. But like Mud said the manufacturers are behind the times.

 

[HARPERC]

Changes in bullet technology, changes in how we use bullets, a back and forth between consumer demand and supply, shooter perception secondary to actual experience, vs marketing.
The .30-06 started with a 1-10" twist to launch a 220 grain round nose. Changes in other aspects of the game, such as optics, changed the game to hunting at a bit more range. Folks switched to lighter bullets, and the old twist no longer mattered for most .30-06 users.
More changes in technology, more range newer bullets, and we have pushed the envelope once again.

 

[Bigeclipse]

Because for 40+ years, nobody offered much heavier than a 175 grain low BC roundnose or soft point bullet for the 7mmRM in their factory loaded ammunition. And the minimum twist for those is 1:9.5". They are too cheap to update their tooling to accommodate modern twist rates for older cartridges. It's a **** shame, too...Because they think they're saving money, when in reality, they're losing sales, so they're losing a LOT more money than they're actually saving.

If Remington would listen to its customers, I bet you they could be the best selling rifle company on the market once again. But they need somebody to make those choices to progress them into the "now", instead of dwelling on what worked 20 years ago. The game (precision and distance) has changed, the bullets have changed, and gun needs have changed. Companies that don't progress with "the game" get left behind.

If Remington would offer 5R rifled 1:8 twist 7mm barrels in all their cartridges, their 7mm cartridges sales would be through the roof!

I disagree with some of your facts. They are not losing out much in the way of money due to customers. The fact is 95% of your hunters out there are still 200 yards or less shooters. Most of those hunters will only care about the caliber and nothing else. They wont understand twist rate or what bullets to use. They will take their gun to the range with several different factory ammo choices and whatever shoots best is what they will use. Id be willing to bet long range hunting will actually shrink over the years if our country's population continues to rise like it is. I see too many ranges being closed for this very reason....land is going the way of the dodo unfortunately. Now from strictly speaking of long range hunters and shooters, then yes they are losing money but again there are very few compared to the millions of hunters who do not care. Just my two cents.