What twist?

Eric H

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Aug 15, 2017
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Well, I'm pretty sure the 116 isn't stable in my 1-10 twist. Either that, or I'm alot worse shot than I thought I was. And so from what you're telling me, is that I should go with a 1-8 twist perhaps, or maybe a 1-7.5 twist?
The 8 twist is great for the 121gr pushing 3100FPS. The 116 is best in the 1/9. Run the calculation.
 

Zorack

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First of I'm against over rpm'ing bullets. The faster the twist rate the more resistance to the bullet traveling down the barrel. So you get higher pressure and decreased velocity.

The other fact is that higher velocity decreases the need for low number twist rates. Example a 16 inch barrel .223 can shoot a 55 grain bullet fine. Take the same bullets and put them in a 20 inch barrel and they fly through the paper sideways at 100 yards because of the velocity increase.

Shilen sells a 27 inch 9:1 257 barrel or at least they used to. That works very well for my buddies 06 and 115 Bergers. The 121 is longer, but might work fine going faster.
If a manufacturer say their bullet needs a 1:8t barrel then you have to go with that twist. I went with a 1:9t in my 7/300wby and it will not stabilize the 168gr lrx from branes because the twist is not fast enough. So depending on your velocities and what ever bullet you chose needs certain twist rate.
 

sodakota

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Well, I'm pretty sure the 116 isn't stable in my 1-10 twist. Either that, or I'm alot worse shot than I thought I was. And so from what you're telling me, is that I should go with a 1-8 twist perhaps, or maybe a 1-7.5 twist?
So why don’t you want to look at Berger or other sites that calculate whether or not the twist will stabilize your bullet rather than get a bunch of opinions.
 

Eric H

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So why don’t you want to look at Berger or other sites that calculate whether or not the twist will stabilize your bullet rather than get a bunch of opinions.
Berger is a good site and BisonBallistics will even tell you at what speed.
 

hadjii

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So why don’t you want to look at Berger or other sites that calculate whether or not the twist will stabilize your bullet rather than get a bunch of opinions.
Um, because I didn't know they existed. And there's a bunch of really smart people on this site who know about a thousand times more than me.
 

Eric H

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Followed BisonBallistics recommendation and ended up with this.
 

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Prairie

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An experience I had puzzled me for a long time until I did some hands-on research. I had loaded up some Barnes 50 grain Varmint Grenade bullets for a couple of 14:1 twist 22-250's I have. Went to the range and they key-holed that target at 100 yds. Yet, when I loaded up some Hornady 50 grain V Max's, they shot a ragged hole at 100 yds. Well, I was gnawing at my tongue and scratchin' at my desk top trying to figure that one out until I found out that the Barnes bullets were longer than the Hornady's to make up for the lighter weight of the all-copper bullets. Also I found that they would not stable out of my 14:1 twist .220 Swift. I pulled all the Varmint Grenade bullets, loaded them up for my 8:1 twist barrel in my AR-15 and they shot sub zero groups at 100 yards. Problem solved. Findings: longer bullet requires faster twist. shorter/lighter bullet requires slower twist. Also found that shooting light and shorter bullet at a faster twist rate and higher velocity tended to come apart. This is probably know by a lot of shooters but just my experience finding out for myself.
 

ButterBean

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I need a twist recommendation for a 25-06 to be able to stabilize the hammer 116 grain and/or the 121 grain hammer hunters. The 1-10 twist that my Winchester 70 isn't doing it. At a hundred yards, accuracy is not good at best, and just not acceptable. Thanks

257 Cal-121g Hammer Hunter​


In stock and ready to ship!
Rated 5.00 out of 5 based on 3customer ratings
Recommended minimum twist rate is 1-8

.257 Cal-116g Shock Hammer​


In stock and ready to ship!
Rated 5.00 out of 5 based on 1customer rating
Recommended twist rate is 1-9″ minimum
 

hadjii

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Sep 25, 2012
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Location
Iowa

257 Cal-121g Hammer Hunter​


In stock and ready to ship!
Rated 5.00 out of 5 based on 3customer ratings
Recommended minimum twist rate is 1-8

.257 Cal-116g Shock Hammer​


In stock and ready to ship!
Rated 5.00 out of 5 based on 1customer rating
Recommended twist rate is 1-9″ minimum
Thanks Butter Bean. I'll be indulging in these bullets as soon as I get my 700 ultimate sold, and send off the 25-06 for a rebarrel. Hill Country Rifles is where I wanna go, but I'll be open to other options.
 

sodakota

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South Dakota
Um, because I didn't know they existed. And there's a bunch of really smart people on this site who know about a thousand times more than me.
The trouble with using some one else’s experience is that there are variables. For instance a load that is stabile at 5,000 feet in dry air could likely not be stable at 1,000 feet in humid air. Also a bullet that is stable when shot at 3,500 FPS at a 9 twist may not be stable when shot at 2,500 FPS and 9 twist. Asking people their opinion likely won’t take all the variables into play.
Do yourself a favor and look at sites that can tell you what you need to know with the conditions you’ll be encountering. Don’t be fooling with opinions, it could cost you.
 

Mikecr

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The trouble with using some one else’s experience is that there are variables. For instance a load that is stabile at 5,000 feet in dry air could likely not be stable at 1,000 feet in humid air.
So you know, humid air is less dense.
Also a bullet that is stable when shot at 3,500 FPS at a 9 twist may not be stable when shot at 2,500 FPS and 9 twist.
Where this scenario actually exists (rare) the 3,500fps bullet would barely be stable. Small air density changes would lead to instabilities and poor results there. It's ALWAYS a bad move to rely on velocity to overcome insufficient twist rate, as velocity does not change twist rate.

Folks, when you need to know a bullet's twist requirement, just ask the bullet maker for minimum twist based on which atmospheric standard they're using.
 

BoomFlop

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Oct 16, 2012
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Location
Wisconsin
Still believe in Iowa with an average elevation of ~1000 and weather conditions of approximate 30 degrees, I’d take a 1.94 over 1.49.

If you took out the 121 gr Hammer, then I think a 1-8 twist would probably be fine, but would probably error on the side of a 1-7.5.

Good luck
Steve
 

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