Gain twist...is it better for pressure or precision?
- Thread starter Davo308
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There was a within last 6 months thread on it.
Advantage is a theoretical you may impart less disturbance physically to the projectile by "easing" it in to the twist.
What I took from that thread was really no negatives and only possible advantage especially if paired with a left hand twist.
Might have more info when my LH gain twist Bartlein on order is mated with receiver and stock.
Advantage is a theoretical you may impart less disturbance physically to the projectile by "easing" it in to the twist.
What I took from that thread was really no negatives and only possible advantage especially if paired with a left hand twist.
Might have more info when my LH gain twist Bartlein on order is mated with receiver and stock.
Everything shows it’s better period
Those smart enough to try it, know, it‘s universally better. The question is, what do you want to be better, some think if it is doing what their traditional barrel is going, why bother. But they are not focusing on the pluses, if they even understand them. Most don’t and only focus on a tiny part of the equation. Everything I have read from people who have not tried them, falls amazingly short.
Gain twist is not new, it was just too hard to machine, Pope hand cut his barrels during his reign and his competition results sustained for 17 years. Then the process was lost to time, mainly because of manufacturing.
Fast forward, Bartlein creates a CNC based cut rifle system and Through Their effort has found a great medium for doing Gain Twist Barrels SUCCESSFULLY. Listen to my recent podcast with Frank Green, Benchrest is using them, Service rifle is using them and so am I.
The feedback I get shows no negatives and only positives, theoretical all you want, I am results based and my results don’t lie. It was a waste of time I would have moved on long ago. Instead it’s is the direction I continue to drive, even last week.
I have a variety of configurations, all have worked.
Those smart enough to try it, know, it‘s universally better. The question is, what do you want to be better, some think if it is doing what their traditional barrel is going, why bother. But they are not focusing on the pluses, if they even understand them. Most don’t and only focus on a tiny part of the equation. Everything I have read from people who have not tried them, falls amazingly short.
Gain twist is not new, it was just too hard to machine, Pope hand cut his barrels during his reign and his competition results sustained for 17 years. Then the process was lost to time, mainly because of manufacturing.
Fast forward, Bartlein creates a CNC based cut rifle system and Through Their effort has found a great medium for doing Gain Twist Barrels SUCCESSFULLY. Listen to my recent podcast with Frank Green, Benchrest is using them, Service rifle is using them and so am I.
The feedback I get shows no negatives and only positives, theoretical all you want, I am results based and my results don’t lie. It was a waste of time I would have moved on long ago. Instead it’s is the direction I continue to drive, even last week.
I have a variety of configurations, all have worked.
You look at the standard twist and work around that,
for a 6.5 I would go, 8.25 to 7.5 or 8.5 to 7.5 works too
For a 308, I would go 10.75 to 9.5 or down to 9.25 but I would hover around that, 10.5 to 9.5 ish
for a 6.5 I would go, 8.25 to 7.5 or 8.5 to 7.5 works too
For a 308, I would go 10.75 to 9.5 or down to 9.25 but I would hover around that, 10.5 to 9.5 ish
Gain Twist are not a big mystery, and yes you want a LH
Personally, I don’t bother with a 308, they tend to very forgiving. The gain helps more so with picky calibers.
Think about a slightly faster twist, like for a 308, a 9, sure you can go into the 8s but nah, I personally never had good luck in the 8s, got rid of every barrel I tried. So we know a 10 twist is a great compromise. Works in a 300WM and 308 really well. So to speed that up you want 9tw, so now split the difference
Left hand helps too, I find my wind is much better, more consistent and I am working two opposing forces against each other vs adding them together. The recoil pulse is much smoother too
Personally, I don’t bother with a 308, they tend to very forgiving. The gain helps more so with picky calibers.
Think about a slightly faster twist, like for a 308, a 9, sure you can go into the 8s but nah, I personally never had good luck in the 8s, got rid of every barrel I tried. So we know a 10 twist is a great compromise. Works in a 300WM and 308 really well. So to speed that up you want 9tw, so now split the difference
Left hand helps too, I find my wind is much better, more consistent and I am working two opposing forces against each other vs adding them together. The recoil pulse is much smoother too
if you look at it logically from a mechanical engineering standpoint, it makes sense.
you should be able to achieve higher velocities with lower pressure and bullet deformation by gradually increasing twist.
i wonder if FN will make them CL CHF or if there is any reason they can't be hammer forged?
you should be able to achieve higher velocities with lower pressure and bullet deformation by gradually increasing twist.
i wonder if FN will make them CL CHF or if there is any reason they can't be hammer forged?
I got it dialed in now. Eating Prime 130’s up. Would really like a lighter Prime option though like a 120. That way I can get back the velocity I give up with the shorter barrel
That's actually what led to my question. I was watching a Forgotten Weapons episode on the Carcano.
Gun Jesus said the Italians went that way (gain twist) to get more velocity without higher pressures.
Of course, he's an engineer more than a long range shooter.
lowlight
In the other thread about gain twists I got the impression that you only recommended them if you were going faster than the industry standard twist. For example, in a .264 no reason to go from a 9 to 8... but you would use them if you wanted to get to a 7.5 twist. But I see above that you had a rifle that used a gain twist to get to 1 in 8. If I only wanted to shoot a bullet that was easily stabilized by the standard twist would you still recommend a gain twist to get there?
In the other thread about gain twists I got the impression that you only recommended them if you were going faster than the industry standard twist. For example, in a .264 no reason to go from a 9 to 8... but you would use them if you wanted to get to a 7.5 twist. But I see above that you had a rifle that used a gain twist to get to 1 in 8. If I only wanted to shoot a bullet that was easily stabilized by the standard twist would you still recommend a gain twist to get there?
If you're referring to my rifle, I used what Bartlein recommended when they spun the barrel for me. The point of gain twist isn't necessarily get you to unconventional twist rates it's more to give the bullet a gentler start instead of going 0-8 instantly.
There is evidence that the GT barrels have harmonic dampening properties they tend to reload easier too
On a semi auto that would also help, so it’s not always about the number.
On a semi auto that would also help, so it’s not always about the number.
Just did a gain in 6.5prc. LH 8.75 to 7.75. But i also have no desire to shoot 150gr bullets. Iwould rather have 130s and 140s shoot well. Would it help ease jacket pressure at extremely high velocity? For example: a 30cal 130or 140 at 4,000fps doing a gain of 1:14 to 12? I know the standard is 3/4 inch change.
Have you notice any gain in velocity with these barrels. I have a gain twist LT 6BRX that gets me insane velocities with no pressure signs and no wear on the press such as loss of primer pockets. Sorry If this has already been addressed
twist shouldn't have a huge effect on velocity, that's more of a barrel length equation, but it should theoretically get you better stability and maybe slow velocity decay out to longer distance.
More twist should increase drag and friction on the bullet. It stands to reason, less twist and less grooves will reduce friction allowing the increased possibility of velocity.
If that was the case we’d all be running a 1:24 twist instead of 1:8’s
I don’t think a 1-24 is going to stabilize a 105 do you have any real world experience with this or just theory
It was a sarcastic response to the post right above it
It was a poor attempt at sarcasm. He used 24 twist as an example when i was using 12 to 14. So he slightly exaggerated the numbers in my post. Tools are everywhere. I had asked a question about some work done a few years ago by some in arizona who pushed a a 130gr barnes 4100fps in a 30 cal. They used slower than 12 twist in the beginning. Later it got slower and the accuracy was .5moa. Guess ya got to tow the line around here, no outside the box topics.
No outside of the box is all good.
But dont you think that if, for example, the Marines, could simply slow the twist on an M40 barrel and gain velocity from the 165's they would have done it? Stability is a product of twist and velocity. too much twist and not enough velocity = unstable, too much velocity and not enough twist = unstable. In Litz book AB For Long Range Shooting, he discusses this on Pgs 158-159 when he discusses stability factor. I mean in a 6.5cm if running a 1:10 instead of a 1:8 made them faster we would all be doing it right?
It’s not about the stabilization factor or even the I velocity I was asking about pressure. You have less pressure on the bullet at 8.2 than 7.5 so you are able to run at higher pressures which gives you higher velocities. This has been stated by several people there is less initial pressure on the bullet with a gain twist. Your examples all go to the the extreme also we aren’t talking about changing the twist by 2-20 .7-1 is more realistic.
Simply changing the twist obviously wouldnt speed the bullet up, it would allow for the bullet to be sped up without tearing jackets.
The “pressure” advantage of a gain twist is initial reduced aerodynamic torque. Instead of going instant 0-100 it gradually gets to 100.
Your original question asked if there was any observed gain in velocity with these barrels implying that twist was somehow correlated with velocity.
Do you own a gain twist? My guess is No so your opinion is irrelevant.
Maybe you should read the thread before spouting off about an opinion of which you don’t like the answer. Posts 8, 14, 19 for example.
Maybe you should all keep your opinion to your self because I didn’t ask any of you for it.
Buddly is that you?
Anybody have any comparative data between gain twist and non gain twist barrels regarding life before seriously degraded accuracy or maybe rate of throat erosion? I’m wondering if you guys who have shot out a few of each have found that you have to start chasing OAL sooner with a constant twist barrel vs gain twist? Also, have you found that gain twist barrels prefer drastically different powder charges or different types of powders than constant twist?
How tight of a gain twist has been experimented?
I’m thinking about a short barrel shooting heaviest per cartridge projectiles
I’m also thinking of trying a .172 barrel and curious what upper limits have been explored already? Like has anyone Tried a 2”per ‘ gain?
I’m thinking about a short barrel shooting heaviest per cartridge projectiles
I’m also thinking of trying a .172 barrel and curious what upper limits have been explored already? Like has anyone Tried a 2”per ‘ gain?
I have a 13 to 5 338, and the service rifle guys do 14 to 6 in their 223
I would stick to 1, but you can try 2,
I would stick to 1, but you can try 2,
i find i learn more when listeningMaybe you should all keep your opinion to your self because I didn’t ask any of you for it.
Curious, why do you figure so much for those type of rifles.
The reason I ask is that I follow the gain barrels, mostly in a BR environment and when Frank started to get a fair amount of the 6mm ‘s out there they had about 1” of gain but the current popular ones, now, only 1/8”.
myself and a couple others are just starting out with them 13.875”-13.750” gain.
Is it all about longer/higher bc bullets?
Yes the 338 i have was for a spefic very long solid.
The service rifle is, this is my understanding, one rifle to shoot the 52gr to 90gr. There is a video but its been years since i watched it.
Bartlein said the BR crowd was going very minimalist, probably goes back to twist rate overall. The BR world favored a slow rate, we are a tick faster now. So maybe it matches ?
I just have not explored all the variables, too many really.
The service rifle is, this is my understanding, one rifle to shoot the 52gr to 90gr. There is a video but its been years since i watched it.
Bartlein said the BR crowd was going very minimalist, probably goes back to twist rate overall. The BR world favored a slow rate, we are a tick faster now. So maybe it matches ?
I just have not explored all the variables, too many really.
Benchrest uses slower twist rates than we do most of the time
If we use a 10, they might be 12 to 14, that is what I mean, they don't want to overspin like we do. Overspinning has the potential to disfigure the bullet more, so it could negatively affect their accuracy. We overspin to shoot farther as spin does not fall off like MV, so if we spin it harder it passes transonic in a better position.
So what Bartlein told me is the BR crowd is starting to use GT Barrels, but the transitions are smaller, without asking I was speculating that it balances the slower spin speeds better.
If we use a 10, they might be 12 to 14, that is what I mean, they don't want to overspin like we do. Overspinning has the potential to disfigure the bullet more, so it could negatively affect their accuracy. We overspin to shoot farther as spin does not fall off like MV, so if we spin it harder it passes transonic in a better position.
So what Bartlein told me is the BR crowd is starting to use GT Barrels, but the transitions are smaller, without asking I was speculating that it balances the slower spin speeds better.
I understand now what you mean.
the BR twist rate is not about bullet disfigurement but the fact that, since nobody probably makes consistently perfect bullets, you want the slowest twist to keep stable since faster will magnify any imbalance within the bullet, most of which seem to be in jackets,
Lots of guys making unbelievable bullets given how many teen aggs are being shot.
Thanks
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So...
I heard about the whole gain twist thing through the everyday sniper and ordered a gain twist Bartlein from Compass Lake Engineering in 223. Here in the formerly great state of Kalifornia I am fortunate enough to shoot squirrels with unleaded bullets (thank you government overlords) and am also very intersted in 223 for long range, as here in SoCal long range is relative.
I can say I've killed quite a few squirrels with unleaded ammo, which is a whole new set of problems when it comes to reloading. I am going to start doing some long range (again, relative to SoCal and 223) testing soon and will post updates.
I heard about the whole gain twist thing through the everyday sniper and ordered a gain twist Bartlein from Compass Lake Engineering in 223. Here in the formerly great state of Kalifornia I am fortunate enough to shoot squirrels with unleaded bullets (thank you government overlords) and am also very intersted in 223 for long range, as here in SoCal long range is relative.
I can say I've killed quite a few squirrels with unleaded ammo, which is a whole new set of problems when it comes to reloading. I am going to start doing some long range (again, relative to SoCal and 223) testing soon and will post updates.
This concept makes sense to my small brain. Does the gain increase uniformly over the entire length of the bore? In other words, if I wanted a shorty I couldn’t just get a standard blank and chop it right?
Correct. That perhaps one disadvantage to the gain twist. You can’t chop when the chamber is shot out cause you will also be changing the twist and would likely have no clue what the new one is, but there is probably a way to figure it out
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