Ep. 085 - Let's Talk Twist Rate 

Wow! This is IT! The deep dive into stability, twist, weight is spectacular. Both of you have a great depth of knowledge and it is fantastic to hear you both share what you have learned. Thank you.

I very much enjoy the technical info that Jayden and others bring to the podcast. I am currently not able to get out and do any actual shooting and I spend a lot of time watching technical videos like this one.

I enjoy both the information and Jayden

Very interesting, very informative. Things have come a long way since I first started reloading in the late eighties. Thank you

50 years of casting and reloading pistols rifles shotguns muzzleloader , Been long journey thanks to Hornady

Jayden is the Chuck Norris of ballistics.

Thanks for the enlightenment!😊

Love it every video I watch of Hornady I get so much info my head just might explode thanks.

Interesting, wasn't really aware of anything other than Greenhill, but, haven't had the need to worry about twist rates other than for cast bullets, and the ones I've shot, were pretty conventional. I blew up some .22 cal 45gr Sierra Hornet bullets one day just to see it happen, was interesting, but, no huge deal. Decent episode.

So all things the same, a 26 inch barrel will spin the bullet faster than an 18in. Does 4dof help find the optimal twist rate for specific barrel lengths?

What about gain twist ? Are pistol bbls twist rate too slow with longer copper slugs ?

1:07:28 I'd say both, the "Information" and "Jayden". I say that because info is one thing but how that info is presented to the receiver is another and that presentation aspect is "the person", hence both the info and Jayden. Anyone can present good information but how its presented plays heavily in how well the receiver absorbs and understands that information. Many people are extremely smart in their area of expertise but some can not present it in a way that other will absorb and understand it.

The 10% error makes me wonder if I could try a 160 grain bullet (hand loaded, of course, since nobody makes a cartridge) for my 270 WSM with a 9.5 twist rate - Nosler has a 160grain ABLR that I assume is made for the 6.8 Western, and it says it needs a 9 twist rate, but 9.5 isn't that far off ... I don't yet reload, but I'm seriously considering it, for things like this (and because cartridges are hard to find, and way expensive up here in Canada) - I know Nosler now has a 150 grain ABLR in a 270, so I could reload using that bullet, but I am curious about the 160 - if I was to figure out how to set it up to have a muzzle velocity of around 2850, maybe that would get me close to gyroscopic stability as it uncorks... I chose 2850 fps because I expect the 150 grain to leave the muzzle at somewhere around 3100 fps (although the 145 grain ELD-X is somewhat higher) - my point is that I've seen a couple of guys fire that 160 grain bullet from their 270 wsm (on YT) while trying to hit 3000 fps- while not seeing keyholes on the target (at 100yards), and the 160 grain bullet might uncork at a high number under normal loads, but if I was to lower that a bit, that would bring the chance of stability up, closer to optimal, as it leaves the barrel... It would be interesting to try - though it would probably be less expensive to just use the 150grain ABLR that the rifle is made to shoot - but that 9.5 twist rate, with that 160 grain, with a lesser powder load to give me lower fps ... Tempting to test...

Great podcasts. But your history went right past the Baker Rifle used by the British Rifle Regt since 1803.

Comment for the algorithm ; Man with beard and baseball cap speaks much truth about ballistics.

Wait... what happened to the 8.6 conversation? It's challenging the traditional expectations, but all we got was a short name-drop. In addressing the terminal effects the example wasn't applicable to the name drop and then the topic just switched and went away. 🤷‍♂️ 🧐

How many bullets do we need to send in to have it added to 4dof? Inwould like the berger 200.20 x 30 cal added

Who is Ft. Sill Alumni ? (your symbol ! USAFATC)

More Dogma

I feel slowing down the twist rate for 22 creedmoor was a poor choice. You’re slowing it down so people can use lighter bullets, that they’d already be using in their 22-250 or 220 Swift. Instead of giving the faster twist rate to fire the heavy bullets, like the 22-250 and 220 Swift guys rebarrel to do.

In my opinion hornady is second to none,

You asked the audience to comment on whether we are drawn to these podcast episodes just for the information or if Jayden is the draw. My answer is “yes”.

I know my 8.6 blackout gang is here.....

I feel like there are legacy cartridges that can benefit from faster twist to take advantage of modern heavier bullets. For example the 25-06 is handicapped by slow twists and lighter bullets. A 7”-7.5” twist with the 130gr class bullets puts that caliber in a whole different league.

After your indepth teaching that 98% of all I've learned from most shooters is hog wash. Thanks guys.

Is there any data on barrel life difference with going to a faster twist rate? I know the faster twist per caliber all things being equal produce more heat because of the increased internal friction. No mention of gain twist rifling. Listening to Frank Green his research has led him to believe just a small gain in twist drives the projectile better applying an increasing load. Verses a more stagnant force being applied to the jacket. In my mind “if” the twist was not perfectly consistent the projectile might rattle in the rifling. Joe Carlos talked about his research led him to believe heavy per caliber bullets benefited from a gain twist IE 90gr .22cal. As he feels they skid some while accelerating a “heavy” bullet to a high RPM. For me the proof is the true match barrels I own shoot such a wide variety of ammo well verses factory barrels have only a couple they really like. This tells me that the ammo out there is really good by and large but the barrel usually screws it up in one way or another. Thank you again for making my lunch breaks so informative!

🤠 Regarding the Faster Twist Barrels for the 270 Winchester in other Factory Rifles, You do have other rifle options Now! Howa makes it in a 1 in 9 twist barrel, Savage in 1 in 8 1/2 barrel, and I believe both Winchester and the "New" Remington Arms Company (Among "Others") is putting on a 1 in 8 twist barrel now! Browning's X-Bolt is in a 1 in 7 1/2 Twist Barrel too! Lots more options are on the way (comming), but what will be the best rifle twist choice? 🤗

🕵️‍♂️ This was the BEST PRESENTATION TO DATE! 😃 Hats of to Jayden (Spelling?)! 🎩 One Important Suggestion: To "Get Ahead of the Curve" it would be Wise to Give This Presentation to Gunmakers in More Detail! Currently, We have Alot of Gunmakers Starting to Make the 270 Winchester in Faster Twist Barrels, but With "NO CONSISTANCY" in Twist Rates! 🤯 Twist Rates from 9 1/2, 9, 8 1/2, 8, and 7 1/2! So, I Don't Know If They Are Guessing What Heavier Bullets That Bullet Makers (Like Yourself) Will Be Making For This Caliber in the Future, or If They Just Don't Know What They Are Doing? 😂 Thus, It May Be Wise To Open Those Lines of Communication NOW, Before Mass Production of These Rifles Begins - Causing Mass Confusion in the Industry? I Assume (As An Engineer, You Won't Here Me Saying That Often) That As We Approach The 100th Anniversary of the 270 Winchester, We a Are Going to See More Heavy Bullet Options and Alot More Rifles Sold in this Particular Cartridge (My Personal Favorite)! 🥳 Thus, It Would Seem "Prudent" If Everyone Got On The Same Page NOW!!! 🤷‍♂️

Great content for those of us who are reloaders, knowledge is accuracy in the end , I’ve loaded all calibers that I’ve owned , many different? But to a real reloader, learning never Ends

It's both. Jayden takes a subject that most of us look at as complex and makes it fairly easy to understand. It's one thing to understand how something works, it takes a true understanding of the subject to explain it in a way that anyone can understand

Great podcast as always. Jaden is super smart and he so good at explaining things . Need more Jayden podcast please. The people doing the hiring at Hornady knows how to pick the right people.

Your C X bullets shoot awesome in 8.6 Blackout. I never thought a Barnes would shoot but it is neck n neck with yours. Please expand thanks been shooting your bullets for 60 years

Just started watching, but I wonder if you all knew, that Rifling was at one time banned by the Church for being some kind of black majic or the work of the Devil 😈

I do not understand why twist is not measured in caliber multiples rather than inches. Navy does it right.

I'd be really interested in subsonic and transonic variables. Bullet design, twist rate etc. Such as 22lr and 300 blackout.

56:57 just tested my 8.6 subsonic loads -SST 225 gn @ 1014fps. Interesting that I found the copper jackets downrange at the 100 yds. It reached since I saw the splash but interesting how the Copper jacket separated from the lead but can’t figure out if the copper unraveled at impact or on its way?

1:3 twist 8.6 blackout thoughts.

Unfortunately, one I'm struggling with is the Hornady Sub-X 175Gr. in .308 and it's not in 4DOF. 8( How come no stability stuff for the Sub-X's? Seems like the LOW velocity loads are the most important to keep this number accurate. I'm using a 1:10 twist .308 and at 1100 fps, it should be stable, but a couple are flipping inside my suppressor. 8( I love the information and like Jayden. ;)

THANKS FOR EXPLAINING SOME OF THE "PHYSICS" AND AERODYNAMIC VARIABLES INVOLVED,..... [IMHO: ...IT WOULD'VE BEEN USEFUL TO HAVE A FEW WHITE-BOARD DIAGRAMS, OR, "GRAPHICS"...]

One of the best podcasts you've put out. I have battled people for years that always said, "you can't over spin a bullet." My basic understanding of external ballistics knew they were wrong. But this podcast was my validation from a true industry professional.

An out of balance tire can have a zone where it is out of balance. My wife’s car has one that is out between 25 and 45mph. It gets more pronounced as the speed increases, then it stabilizes. Do bullets have a zone like this?

As far as why we like jayden it is both. The topic and his knowledge of the subject is what i like.

I was hoping that you would address the relationship between spin rate and dynamic stability. I’m glad you acknowledged its omission at the end. It is my understanding that dynamic stability is far less deterministic than gyro stability… which makes it far more difficult to understand and thus makes it interesting enough to warrant its own episode. Wink wink. 😉

I have a 22-250 fast twist. This was good information.

Great podcast gentlemen! One potential follow up topic: I’d love to hear more about over-stabilization and it’s effects on long range shooting. An over-stabilized bullet will increase its Angle of Attack throughout a ballistic trajectory…which in turn increases drag, etc. I would love to hear what you have studied with respect to long range accuracy and over-stabilization. How do you accurately calculate the proper spin rate for proper bullet “tip over” to follow the ballistic curve? Keep up the great work!

As a physicist, I love these kinds of discussions! Cheers, guys 🍻

The answer to the question about content or person is simple. BOTH !

This was the best podcast/video that I've watched on this subject. The only thing missing was a white board. I would love to see more videos on twist rate and bullet types.and weights. Thanks gents.

“There’s not a bullet out there that needs a 7 twist” maybe I’m totally wrong here but, badlands precision 135 SBD2 and a couple of the hammer lines of bullet absolutely need a 7 twist or faster in the 6.5 caliber. The badlands are ridiculously long and sleek. I shoot that bullet solely in my 6.5-284. I REALLY wish it was in 4dof @hornadypodcast

In short, bare bones. Bullets need spin to be stable. for a given caliber, longer bullets need more RPM to stabilize. RPM can be increased by increasing twist rate or velocity. There are math formulas to calculate this, but honestly, I just use the calculator on Berger's website. A Hornday calculator would be nice....

Given that Tikka and Sako are now producing their .243 calibre rifles with 1:8 twist to accommodate the misguided usage of copper in U.K. and EU, how will this effect the usage of legacy cartridges which were designed around 1:9 and greater in this calibre and similar going forward?

Great information. Thanks Hornady!

This is the best technical podcast out there!

I have seen a number of testers state that faster twist rates generally have a significant positive effect on monolithic copper alloy bullets designed to expand. Those bullets tend to penetrate deeply anyway, so opening a little quicker is not a problem. I wonder if the effect is even greater with bullets that expand into more distinct petals and tend to leave spiral patterns in game or gel. My train of thinking is that possibly more tissue is damaged by is slicing rather than being torn apart as from a classic mushroom-shape. Slicing may not be an accurate description since it may be more from shear from the gaps between the petals. I have heard one three-petal design described as a high-speed broadhead and have seen photos of triangular holes in tissue. I don't know if the number of petals makes a big difference, though. It is possible that the tri-lobed pattern is just more distinct and photographs better. FWIW, extreme twist, as from a 5" twist 300 Blackout has caused premature opening of at least one monolithic bullet. The manufacturer actually modified their bullet to avoid customer complaints as the more rapid twist started becoming more common. As you guys said, faster is not always better.

I have a 10 twist 17 Remington and I would like to assure that it would stabilize the 25 gr Vmax, and I don’t see where it shows up in the BC side of the Hornady app. I can’t use the 4dof side since the bullet is not in that area. I am in south west Nebraska approximately 2100 ft elevation. Also I built a 22 creedmoor on a savage msr long range precision last year and was able to take 4 does with it during lare season

The old Mausers had faster than 1 in 10 twist .

Please give Sharpe's Rifle Company his due in the Napoleonic Wars his due!

Another extremely informative segment. Had to listen to certain sections twice. Oh and answer Seth’s question as to Jayden is the only way I get to watch these segment in the living room during prime time as the Bride thinks he is a handsome lad…

Another Quinlan's Corner!

How would this twist rate vs bore size be figured for a saboted bullet ?? Faster twist for a smaller bullet is it going to be ok saboted ??

Ive learned so much from all of your podcasts, thanks for doing these. This one answered a question ive had for a long time. I run the 230 grain A tips at 2850fps in my 24in 1in 10 twist 300WM(its a long story why i even tried them in the first place) they are very accurate but i wondered if it was going to show itself at longer distances. I know its not the right twist to use but i have hit milk jugs past 1000 yards with it.

My greatest question has always been this: What effect does twist rate have in rotating barrel locking designs?

Good morning, Hornady 😉👊🇺🇸

The best twist rate for 223 and 22-250 is 1:12. Doesn’t matter what people repeat because they heard someone else say it. All the twist rates I have shot for 40 to 55 grains hunting projectiles and maintain a consistent 3/4 to 1/2” groups is a 1:12 twist. Look on the shelf and all the soft point, hollow points and plastic tipped hunting rounds offered by ammo manufacturers in 223 and 22-250 is going to be between 50 to 55 grain. Why these rifle manufacturers no longer offer 1:12 in these two calibers is idiotic. You guys can continue try to reinvent the wheel, but I will stick to my CZ 527 223 with a 1:12 twist which they no longer offer. It really is a shame.

Id like to see a podcast on cryogenic treated barrels . And accuracy gains if any. Great show loved it. Always learning something from hornady

Without having all of the fancy tools being talked about here, is there a number range I should be looking for if I am using the Berger Stability tool? Looking at the heavy for caliber 25 cal rifles and playing with altitude and temperature gives me between 1.6 and 2.0 assuming a MV of 3050 and a twist of 1 in 7 with their Target Hybrid slug. Not sire if 1.6 to 2.0 is good or bad

Because of the info. But would we get it without Jayden?

First, thanks for covering the basics of Twist Rates and their history. How about Left Twist to counter the Coriolis Effect and Gain Twist. My question would be for let's say a 24 inch left gain twist Bartlein SS Barrel 12 1/4 Twist to 12 Twist ( or 12 to 11 3/4 ) for the Hornady 35 Grain NTX 223 Remington Superformance Varmint at 4000 fps. This would be to stabilize this cartridge in a maximal way. I would be shooting prairie dogs early in the day with low wind mostly. Then graduate upward in bullet weight in different rifles and calibers. Now about having multiple rifle profiles in ballistic calculators/devices my philosophy is to have only one profile per rifle. This is because each rifle has only one true zero. At least in my world. I could be wrong but that would have to be explained to me. I have thought of having multiple ballistic profiles per rifle and then a "Zero Dope Card" with the number of range and windage clicks to bring to zero each profile for the same rifle. But I like to stay away introducing potential confusion in my shooting. Your thoughts on this also.

Jayden! Jayden! (Cheering) Thanks for both of you. Thinking about buying the new Ruger American gen 2 in 6.5 creed, or 30-06. What should the twist rate for each be? Thanks

It is important to note that it was only the North that had rifles with miniballz and rifling. The South was broke. They had no money for rifles, uniforms shoes. Boots. Southern soldiers were using their squirrel guns. As a result they could not get any accuracy after 40 yards. Hence the South would March in tight formations as they did on Gettysberg. Causing mass casualties. While the North had new Uniforns, boots, food, new rifled barrels with miniballs. That were accurate out to 2 to 300 yards. In an open field battle like Gettysberg. The South never stood a chance. Let alone the marksman on Little Rountop. Who repelled constant attacks from the South. Which won the battle of Gettysberg. This battle is painstakingly studed at the U.S. MILITARY ACADEMY AT West Point. I encourage everyone to read Shelby Foots writings on Gettysberg. Fascinating.

Came here hoping to learn a lot of things, but especially how the 8.6 BLK bullet can work with 1:3 twist and subsonic velocity. Maybe I'm just not catching the intuition, but it seems to me we discovered the greatest innovation in ballistic science since rifling itself: adding projectile energy via mass, velocity, AND rotational velocity.

So would twist rate be affected by today’s 30-30 whereas it’s not just the old 150/170 weights. The current 30-30 is around 130 through 190. Shouldn’t that raise the twist rate especially on the heavier ones?

In light of Browning producing 1/8 twist barrels for their .270 caliber barrels. Could you elaborate on what has convinced Browning to produce an aggressive twist barrel on their .270 caliber rifles. Thank you.

I feel like you should have elaborated a bit on this topic of rotational energy. Contrary to what is said in this podcast it does help with terminal effect. How could it not if the bullet stays in the target? The question is just how much. By my calculations you can get about 5 % extra energy into a subsonic 300 grain bullet by utilizing a 1" twist barrel. Not a lot, arguably not enough to make it worthwhile, but more than a neglible amount.

Would love for you to have a podcast and explain the Sabatti multi radial rifling.

With modern machining it's possible to vary twist down the length of the barrel, so why not optimize or 'taper' twist between breach and muzzle? Many improvements might be realized (with all other things being equal), including higher muzzle velocities, cooler barrels, reduced report, reduced exhaust, etc..

Burning question: "modern" rubric is "heavier bullet requires faster twist rate"; how does that square with Civil War era designs that have bullet mass in the range of 400 - 500 grains and rifle twist rate in the neighborhood of 1 in 72" ? No response ? Toward the end of the video, "what else" - there is the concept of "calibers per revolution" - so .58 cal fired in 1x72" twist would be ~124 . . .

@practicalaccuracy you see this?

I’m pretty sure that rifling actually came from folks trying to manage Black Powder Fouling. If you’ve ever fired a muzzleloading gun you’ll know that it gets harder to ram the ball home with each shot because of fowling in the barrel. People put grooves in the barrel to give that fowling somewhere to go. It was just a happy accident. Idk about that arrows spin so let’s rifle a barrel nonsense.

Here's a question about something I never hear anyone talk about. Does a barrels twist rate affect muzzle velocity?? Does a tighter twist rate cause MV to be reduced?

Great info. It took me 3 attempts to listen through the entire thing without going Deer in the headlights. Lol. Jayden is great. Looks like your drunk uncle, but speaks like a college professor.

Will the Hornady 212gr ELD-X shoot accurately out of the Ruger Precision Rifle with a twist rate of 1:9?

Will the Hornady 212gr ELD-X shoot accurately out of the Ruger Precision Rifle with a twist rate of 1:9?

Thanks for the insight! Has anyone explained the constant twist rate against the increase in friction down the barrrel? (bullet starts at zero-friction/max-pessure and increases friction and loses pressure as it accelrates through the path.)

Nice I'm glad I found you guys..I call hornady alot for info on reloading just started reloading about year ago.collecting lead and brass at the range.then making castings and reloading.right now I'm just reloading 9mm.cause that what pistols I have..it's a awesome hobby love it..and I get a lot of firearm practice. And testing my ammo...

How do we not have more problems with 5.56? 720×3200÷7 gets us around 329,000 RPM. Why is 720 a constant?

Explained well !! Educational and knowledgeable

Excellent ,Very Interesting 💯 💥💥💥💥💥💥💥

I like this subject matter. I wanted to ask if there is any concern about matching the bullet spin rate to the natural vibration rate of a rifle barrel? Are the two frequencies so far apart or the amplitude of the barrel vibration so small that it is not a major concern? In the car tire analogy, sometimes the vibration gets worse as you pick up speed, and then starts getting less when you go even faster. Can a rifle barrel vibration and bullet spin be adversely matched?

Interesting picture you show at the beginning. There’s only one barrel in the world that’s made that way. It’s an air rifle barrel. The most accurate barrel in the history of the world made by FX.

Is there a meaningful benefit to rifling that increases spin rate as it goes? If think it would encourage a gradual increase which would be kinder to large lead bullets that might deform too easily and resist acceleration more profoundly if pushed hard. Or it might be a good alternative to really fast rifling so as to reduce overall friction but still result in the proper spin speed upon exiting the barrel.

Seeking is using a 1-10 twist for 300 PRC. Therefore I must rule out Seekins for a 300 PRC.

You said that blunt nose bullets will move the center of pressure to the rear, the more blunt, the more to the rear. If the center of pressure were moved behind of the center of gravity, they would travel truer than modern bullets. You should have said that the blunt nose moves the center of pressure to the front, making them more unstable.

If the bullet you are shooting is listed in 4DOF, than there is no reason not to be using 4DOF.

Explain the reason for an open tip and boat tail bullet for the 6.5 creedmore. What is the advantage of the open tip.

Both

This could have been explained in 1/2 hr. Or less. Too mush idle talk.

Super useful information and I only watch because of Jayden lol

Thank you for the videos always looking forward. It would be nice to find out about powder fill rates for common calibers.

if you reload and do not clean brass interior of carbon residue, is that a problem?