Left-Hand Gain Twist
- Thread starter MarkLeupold
- Start date
I screwed up.
Bought something I wasnt looking to buy.
Now Im planning a new rifle build.
This thread has me thinking of playing with LHGT.
Caliber is going to be .308.
Contour is going to be at least varmint likely heavier once I guesstimate how much wood stock I can have hogged out.
Length - a shorty 18 inches, no more than 22. Still checking "the look". Pretty guns matter.
Cro/Moly carbon steel
Primary bullet intended is 175 SMK.
It will infrequently get to shoot 1000 yards. Most frequent range trips would be to 300.
Was originally wanting a standard fast twist in one of these three flavors 1:9, 1:8 or 1:7.
Now thinking LHGT start at 1:11.25 gaining to the best of the three considered 1:9, 1:8 or 1:7.
Any thoughts from the experienced users/ballisticians?
Will the short barrel cause problems?
At what point do I risk spinning jackets on a .308 175 SMK?
Thanks for any help provided.
Bought something I wasnt looking to buy.
Now Im planning a new rifle build.
This thread has me thinking of playing with LHGT.
Caliber is going to be .308.
Contour is going to be at least varmint likely heavier once I guesstimate how much wood stock I can have hogged out.
Length - a shorty 18 inches, no more than 22. Still checking "the look". Pretty guns matter.
Cro/Moly carbon steel
Primary bullet intended is 175 SMK.
It will infrequently get to shoot 1000 yards. Most frequent range trips would be to 300.
Was originally wanting a standard fast twist in one of these three flavors 1:9, 1:8 or 1:7.
Now thinking LHGT start at 1:11.25 gaining to the best of the three considered 1:9, 1:8 or 1:7.
Any thoughts from the experienced users/ballisticians?
Will the short barrel cause problems?
At what point do I risk spinning jackets on a .308 175 SMK?
Thanks for any help provided.
A 1-7" ending twist would put you around 278,000 RPM at 2700 fps, and I don't think you'll be going that fast. There's no magical number, but once you get up in the 300,000 RPM range and above, bullets start thinking about coming apart. Some handle upwards of that really well, but 300,000 RPM is a decent baseline to start being careful at.
Thank you sir.
I have no clue but do so now, thanks to you.
Most of my reloading ends up the 2660-2670 fps range. For classes I generally shoot FGMM 175 to take my reloading mistakes out of the equation. Boxes of FGMM state 2550 but I seem to get faster readouts from them.
Last time I was having a rifle built it was recommended to me I try a 1:7 range twist as some agency or other was using short barrels/fast twist with good results.
I ended up going 1:11.25 and it shoots great but with this rifle Im going to experiment a little.
If there is any negarive knowledge (or positive) about what Im intending Id love to hear before blowing the money.
Guessing Bartlein will be my barrel builder of choice. Doesnt look like Kreiger does LHGT.
You asked for input from experienced users or ballisticians, so I didn’t answer this morning. However, due to the dearth of responses to your questions I will throw in some free input from someone who only knows enough to be dangerous, but has a real interest in LHGT and as such has read a lot. In other words, input worth exactly what you paid for it. 
What I keep hearing repeated from those that have asked Bartlein is that they don’t recommend much more than about 3/4 of a twist gain for conventional clad bullets. I do not know exactly what factors drive that advice, but it has been repeated. So total hearsay in other words. Based on that information and your wanting a short barreled .308, you might find yourself requesting something like a 1:8 to 1:7-1/4 gain twist or something similar.
Were I in your shoes, I would call or email Bartlein and have a discussion of your wants and intent. Being as they just may be the single most knowledgeable barrel maker currently making gain twist barrels, I would value their input.
I’m interested in seeing how this project turns out.
What I keep hearing repeated from those that have asked Bartlein is that they don’t recommend much more than about 3/4 of a twist gain for conventional clad bullets. I do not know exactly what factors drive that advice, but it has been repeated. So total hearsay in other words. Based on that information and your wanting a short barreled .308, you might find yourself requesting something like a 1:8 to 1:7-1/4 gain twist or something similar.
Were I in your shoes, I would call or email Bartlein and have a discussion of your wants and intent. Being as they just may be the single most knowledgeable barrel maker currently making gain twist barrels, I would value their input.
I’m interested in seeing how this project turns out.
You asked for input from experienced users or ballisticians, so I didn’t answer this morning. However, due to the dearth of responses to your questions I will throw in some free input from someone who only knows enough to be dangerous, but has a real interest in LHGT and as such has read a lot. In other words, input worth exactly what you paid for it.
What I keep hearing repeated from those that have asked Bartlein is that they don’t recommend much more than about 3/4 of a twist gain for conventional clad bullets. I do not know exactly what factors drive that advice, but it has been repeated. So total hearsay in other words. Based on that information and your wanting a short barreled .308, you might find yourself requesting something like a 1:8 to 1:7-1/4 gain twist or something similar.
Were I in your shoes, I would call or email Bartlein and have a discussion of your wants and intent. Being as they just may be the single most knowledgeable barrel maker currently making gain twist barrels, I would value their input.
I’m interested in seeing how this project turns out.
Thank you for the great reply.
Yep I plan to talk to Bartlein after I get out some butcher paper and draw a mock up of the barrel profile based on what I have for wood to support it.
I thought I read somewhere in here there being little limit to the gain but they may be referencing solids not jacketed bullets.
More research required but your response makes sense to me.
With a 308 I would not go to a 7 twist, but 8 is where the sporty 30 cals go
A 1-10 is perfect for a 308, if you were gonna experiment with solids I would do a 308 gain, otherwise, what are you doing with it ?
I would only really consider it with a 300WM in an ELR type situation where you want both some twist option and speed so the bullet is not going to a 7
A 10 to 9 would probably work, or do a 9.5 to an 8.75 if you want play with a 30 cal GT
308s don't really suffer from the speed plus spin issues like other calibers, 6mm or 6.5 where people try to squeeze every ounce of speed out of it while attempting to twist it harder. Which is why most of my GT barrels are other calibers
What happens with over spinning and pushing too hard, you get bullet deformation, sometimes under the jacket which throws the balance off and actually decreases the results. So you GT it to gradually bring the spin up higher,
If I was doing a 20" 308 with a GT I would do 9.5 to 8.75 like I said and try it that way or the same in a longer 300WM to keep from stacking on issues
3/4 gain is because Jackets can rip or tear or the lead will move under the jacket, solids can be pushed harder and fast so deformation is not an issue, hence the ability to spin even faster.
There is a point when trying to experiment you can play the game off the field, vs staying on the course, with less gain.
My 338NM made specifically for solids is a 13-5.4 Twist and using a jacketed bullet in that will probably hurt ya. Then again the 223 crowd runs 14-6 twist for their Service Rifles so they can shoot everything from lighter bullets close to really heavy far and it works for them.
A 1-10 is perfect for a 308, if you were gonna experiment with solids I would do a 308 gain, otherwise, what are you doing with it ?
I would only really consider it with a 300WM in an ELR type situation where you want both some twist option and speed so the bullet is not going to a 7
A 10 to 9 would probably work, or do a 9.5 to an 8.75 if you want play with a 30 cal GT
308s don't really suffer from the speed plus spin issues like other calibers, 6mm or 6.5 where people try to squeeze every ounce of speed out of it while attempting to twist it harder. Which is why most of my GT barrels are other calibers
What happens with over spinning and pushing too hard, you get bullet deformation, sometimes under the jacket which throws the balance off and actually decreases the results. So you GT it to gradually bring the spin up higher,
If I was doing a 20" 308 with a GT I would do 9.5 to 8.75 like I said and try it that way or the same in a longer 300WM to keep from stacking on issues
3/4 gain is because Jackets can rip or tear or the lead will move under the jacket, solids can be pushed harder and fast so deformation is not an issue, hence the ability to spin even faster.
There is a point when trying to experiment you can play the game off the field, vs staying on the course, with less gain.
My 338NM made specifically for solids is a 13-5.4 Twist and using a jacketed bullet in that will probably hurt ya. Then again the 223 crowd runs 14-6 twist for their Service Rifles so they can shoot everything from lighter bullets close to really heavy far and it works for them.
Thank you for the common sense.
When this is the technology your dicking with.......
Maybe old school is where to stay at.
Dude, their is nothing negative recoil wise about a LH gain twist barrel chambered in .300 win. Call bartlein they will make one for you.
D
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@lowlight
I'm interested in the gain twist concept but have no experience with it. So, I have a question.
It seems everyone is talking about one twist ratio vs. another,(10-8 gain twist for example) but how does barrel length affect a given ratio on the target and in load developement? A 10-8 gain twist in a 16" barrel would necessarily be a much faster transition than in a 26" barrel.
I haven't read anyone addressing this aspect and would appreciate your thoughts and experience on it.
I'm interested in the gain twist concept but have no experience with it. So, I have a question.
It seems everyone is talking about one twist ratio vs. another,(10-8 gain twist for example) but how does barrel length affect a given ratio on the target and in load developement? A 10-8 gain twist in a 16" barrel would necessarily be a much faster transition than in a 26" barrel.
I haven't read anyone addressing this aspect and would appreciate your thoughts and experience on it.
Regardless of how fast the transition is, the bullet deformation as the rifling surfaces twist is going to be about the same, since the initial and final inscribed helix angles will be the same.
I can’t tell you anything about how other factors may impact performance.
In my experience,
The benefit to the GT is the ability to keeps the speeds up while twisting it faster
When you don’t have the velocity it’s not going to affect the bullet the same as if it’s pushing it faster. I have a short 7 twist 260 that does well but the velocity is at least 150fps slower than my GT 260
This has been part of the issue with spin talk. The Army when listening to some about twisting faster we’re seeing it done in very short barrels (14”) covert type rifles. But in practice they always go longer like 24” then lament the results are not there and switch things up. In their 260 they had to switch bullets in the 300NM they just plain bitch the caliber won’t shoot anymore. When guys were using a 10 twist 26” barrel great, they see an 18” - 8 twist demo and decide to do an 8 twist 26” and suddenly there are problems.
I think if you go short it’s a wash, just use the desired exit twist like a 7 twist 6.5, but in cases of barrels over 20” opt to use a GT instead.
I have both and feel it’s not necessarily a one stop solution it’s more of putting the twist into context of its use.
The benefit to the GT is the ability to keeps the speeds up while twisting it faster
When you don’t have the velocity it’s not going to affect the bullet the same as if it’s pushing it faster. I have a short 7 twist 260 that does well but the velocity is at least 150fps slower than my GT 260
This has been part of the issue with spin talk. The Army when listening to some about twisting faster we’re seeing it done in very short barrels (14”) covert type rifles. But in practice they always go longer like 24” then lament the results are not there and switch things up. In their 260 they had to switch bullets in the 300NM they just plain bitch the caliber won’t shoot anymore. When guys were using a 10 twist 26” barrel great, they see an 18” - 8 twist demo and decide to do an 8 twist 26” and suddenly there are problems.
I think if you go short it’s a wash, just use the desired exit twist like a 7 twist 6.5, but in cases of barrels over 20” opt to use a GT instead.
I have both and feel it’s not necessarily a one stop solution it’s more of putting the twist into context of its use.
I think @lowlight nailed it pretty much. I have two GT barrels. On a 20” GT 260 gas gun I don’t think I see the benefit since I’m already giving up so much speed in the 260 with a 20” barrel. That build was more an experiment in building a tac driving DMR rifle best suited for 800 and in with the ability to go further if need be better than a 308.
the other rifle is a 6mm creed. I have t received it yet but I’ll let you know once I do and get to shoot it. That’s a 24” barrel.
both are also Left twist as well.
I do intend to go short barrel on a new build.
Im understanding Gain Twist will likely not gain me anything.
But.......for a righty in the Northern hemisphere there may be slight advantages in LH twist that Pope had discovered years ago.
For an 18 inch .308, a LH twist will give me that minute advantage over the factors a spinning earth cause and it will induce a recoil impulse more user friendly to a right handed shooter.
Is this correct?
Ill probably just go tried and true 1:10 LH twist and satisfy my curiosity yet should understand I lack the skills to ever be able to take advantage of the spinning earth benefits.
I do sense "twist" imparted by a bullet travelling down a barrel though, especially when firing a pistol.
Never really considered the tourque effect with a rifle but Im sure its there.
Im guessing that will be something I will notice with my new build.
Interested in fast twist .308 but that's probably a topic for another thread.
Im understanding Gain Twist will likely not gain me anything.
But.......for a righty in the Northern hemisphere there may be slight advantages in LH twist that Pope had discovered years ago.
For an 18 inch .308, a LH twist will give me that minute advantage over the factors a spinning earth cause and it will induce a recoil impulse more user friendly to a right handed shooter.
Is this correct?
Ill probably just go tried and true 1:10 LH twist and satisfy my curiosity yet should understand I lack the skills to ever be able to take advantage of the spinning earth benefits.
I do sense "twist" imparted by a bullet travelling down a barrel though, especially when firing a pistol.
Never really considered the tourque effect with a rifle but Im sure its there.
Im guessing that will be something I will notice with my new build.
Interested in fast twist .308 but that's probably a topic for another thread.
I have just begun working with a new Bartlein gain twist 308 win barrel it starts at 11 and ends at 10. My first observation is possible lower pressures I am pushing a Berger 200.20x bullet at over 2600 FPS out of a 28" without flattened primers. Time will tell
Figured my desired barrel profile.
Ill end up with 21 inch OAL +/- from breech face....
1.25 cylinder at 4 inches, Straight taper to .90 inch.
Ill give @lowlight suggestion a try 9.5 to 8.75 LH gain twist. Doesn't sound extreme in any measure.
Purpose occasional classes/range use that will infrequently go to 1000 yards with target sizes being greater than MOA.
Most frequent use will be local at either a 100 yard or 300 yard range holing paper shooting at 1 inch and 3 inch circles with desire to get 20 holes inside the circle.
Intended ammo 175 SMK @ FGMM velocities.
Why?
I have a scope on hand that needs a home, I came across a cool piece of wood, I want to try something different from what I have.
Thinking biggest benefit will be having the rifle twist into shooters mass rather than away.
Never paid attention to that aspect before but last range session I made the conscious effort.
Sure enough comb of stock wants to twist off of cheek weld as shot is fired.
Sent contact message to Bartlein earlier in week. Expecting holidays will delay any reply.
Guessing lead time to be about 6 months which will kind of blow.
Ill end up with 21 inch OAL +/- from breech face....
1.25 cylinder at 4 inches, Straight taper to .90 inch.
Ill give @lowlight suggestion a try 9.5 to 8.75 LH gain twist. Doesn't sound extreme in any measure.
Purpose occasional classes/range use that will infrequently go to 1000 yards with target sizes being greater than MOA.
Most frequent use will be local at either a 100 yard or 300 yard range holing paper shooting at 1 inch and 3 inch circles with desire to get 20 holes inside the circle.
Intended ammo 175 SMK @ FGMM velocities.
Why?
I have a scope on hand that needs a home, I came across a cool piece of wood, I want to try something different from what I have.
Thinking biggest benefit will be having the rifle twist into shooters mass rather than away.
Never paid attention to that aspect before but last range session I made the conscious effort.
Sure enough comb of stock wants to twist off of cheek weld as shot is fired.
Sent contact message to Bartlein earlier in week. Expecting holidays will delay any reply.
Guessing lead time to be about 6 months which will kind of blow.
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I have a few questions for @lowlight or others with GT experience.
A little background for my questions, I'm a left handed shooter with a Surgeon 260rem bolt gun, 22" barrel with a Can. I typically go with 1-8 twist and shoot burger 140 match hybrids. MV is around 2760. My next node is around 2830-2840 or so, but I feel I'm on the edge because I sometimes get pressure signs at 2830 (sticky bolt).
1). as a LH shooter, is a LHGT a viable twist direction. I ask because a lot of conversation revolves around RH shooters.
2). Could is expect any gains with a 22" barrel?
3). Would a GT help me get to 2830-2840 without pressure signs?
4). Based on answers to the above questions- if there are no negatives to trying a GT next time I change tires, what would a recommended twist be for 130-140 gr. bullets (and I'm sticking with 260Rem)?
From my limited experience using gain twist on a 308 Win, I believe you could achieve the velocities you are asking for with less pressure if done right. In my load development I was able to push a 200 20x Berger at 2700 FPS with only a start of a flattened primer. That seems to be almost unheard of speed for a 200 grain out of any length barrel from what I can find. My barrel is a Bartlein, starts at an 11 and ends at 10. Maybe you could do a 9 twist to 7.75 or so?
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Not to revive a dead thread but I've ordered several bartlein LH GT Gain Twists (not gay tiger) and are being spun up for my mrad. Hoping the results are good as I am pursuing a 1 inch gain such as 6.5saum 1/9 to 1/8 at 26inchs. .338 Lapua 28inch & 33XC 32 inch 1/10.5-1/9.5 37XC 32 inch 1/11-1/10. Will keep you guys posted on my results.
Received 2/5 barrels so far, 6.5 barrel is at GA Precision. Waiting on some more money to buy reamer, brass & accessories for the 37xc.
Take a look at the hoplite thread for possibilities...
LH gain 300 Norma shooting factory ammo
7 of 10 at 1 mile 24” x 24” plate.
Yea, I'm following that thread. I've been thinking about doing a 300 norma. At this point though I've paid for the barrels I have on order. I'd have to get another extension and barrel.
I appreciate this thread and the people who posted. I ordered a 26" LH GT for my AXMC in 260R. I've not been able to find an AXMC barrel in .260 with the specs I wanted, so I called Adam at MileHigh and they had one .264 Bartlein blank with a GT of 8.7 to 7.6. I should have it in 3-4 weeks and I'll slap it on and see what it likes.
Yep!
The caliber/contour/carbon fiber etc...we can do the rifling pretty much anyway you want it. The outside of the barrel is mostly looks and effects weight etc...
If any of you guys have updated experiences on a 6.5 CM in left gain I'd love to hear them. Seems all aces from the various threads I've read. Currently have a Proof pre-fit 26" shooting 140s outstanding just probably over it's half life so starting to sniff around for who has what in stock as I'll probably drop a new barrel within 4-5 months. Can't believe I didn't pay attention to the GT conversation....only so much time to devote to the webs!
I'm sure you are excited.....that's a drool cup to the left right? I have one too when gear is on order/build process.
Any kind of lead time for current order heads up? 6 months? Year?
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We're quoting around 10-12 months.
We have have only a handful of orders left to fill from Dec.2020. Those should all be wrapped up this month.
Later, Frank
Bartlein Barrels
You have to do builds on it, but MHSA often has LHGT Barrels in stock, you just need to build something on it as they don't sell the blanks alone
If you spun it up with them, depending on the caliber, they often have them
If you spun it up with them, depending on the caliber, they often have them
Does anyone have actual experience with this. I was given similar advice when looking into barrel blanks for a build. So say 300 PRC, maybe 10lb rifle, 245gr bullets at 2900 fps, 8 twist is it going to hit your cheek enough to justify going RH twist? I'd rather just get the Left Hand Gain twist unless I am going to regret it... With a 12 month lead time, and the cost to go 400MODBB Carbonfiber, I don't want to get it wrong.
I wouldn’t be concerned unless you regularly keep an inch between your chin and the cheekpiece. I can run the math, but meh.
I totally agree but have seen/heard it will be an issue from enough reliable sources to raise concerns. I don't want to drop $1k on a Carbon fiber 400MODBB barrel, inlet it into an expensive English Walnut stock and then have a problem with the rotational recoil.
Recoil is not pushing it into or off your chin,
Who ever sold that bullshit has no clue, this is not a light caliber only thing ,
Gain twist work better, bet me real money you’ll lose
Who ever sold that bullshit has no clue, this is not a light caliber only thing ,
Gain twist work better, bet me real money you’ll lose
He is referencing felt torque imparted to the rifle as it travels down the barrel.
Super noticeable in pistol if your habit is to always shoot two handed and you find yourself doing a one hand drill. Assumed it is similar in rifle but mitigation is a function of proper rifle positioning. If torque is a problem you are not addressing the rifle properly.
The concept was mentioned two years or so ago in this thread.
Just seems like there is no down side to LHGT and the benefits are not huge but for you guys that compete to the 9th degree why not take every advantage even if incremental.
If you’re not controlling torque you deserve to get whacked. If you are controlling torque, you’ll be fine.
Reminds me of people’s fear of recoil w shotguns.
“Won’t it bang me in the face or shoulder?”
“Not if you have your head on the gun and butt firmly in your shoulder…the way we have been telling over and over again “
Lol
“Won’t it bang me in the face or shoulder?”
“Not if you have your head on the gun and butt firmly in your shoulder…the way we have been telling over and over again “
Lol
GT has been around forever….at least since the mid 1800’s.
Remember back in the hey day of schuetzenfest shooting/rifles….Off hand rifles had a weight limit of 10.5# if I recall correctly. An average caliber was .38 and .40 caliber. Later on .32 and even .28cal. The average bullet weight of a .40 was 330gr.
Pope would only make LH twist barrels. He said all the south paw shooters could suffer. Think of those heavy bullets and being a right handed shooter in a light weight rifle. That was one of the things he always said, “it helped the shooter control the rifle better.“
He also stated that the GT helped reduce fouling (remember these are lead bullets these guys are shooting) and that the bullet started easier into the rifling. I’ve got his book and actual word for word comments at work and I can post them on Monday if you like.
I just recently sold a Marlin Ballard #4 variation Rigby Ballard offhand rifle that Pope converted to 22rf. The barrel had 8 grooves, left hand twist and was a gain twist. From what I could measure I would say it was a 18 to a 16.5 twist. The bore condition of the rifle was flat out mint and it was made around 1905.
Steve Garbe asked me if he could put the rifle into a Pope machine rest that he had (gun was sent to him to repair the original broken stock) and shoot it. I told him to knock himself out. That gun shot 10 shot groups in the low .3xx’s at 65 yards outside. Wasn’t shot in a indoor range. Even new guns made now a days would have a tough time beating that. A action/rifle made in the late 1800’s (think it was around 1885ish) and a barrel made well over a 100 years ago.
I’ll post a picture of the rifle on Monday. I’ve posted it before on the hide somewhere.
My personal opinion is the GT and direction of the twist can help you with the bigger heavier bullets/more recoil type guns.
As Lowlight has stated and in the case of the 22rf I just pointed out…it’s not hurting you at all. That’s for sure.
All of my personal RF barrels are gain twist. Those soft lead bullets….the gain twist is always putting a fresh bite on them as they go down the bore. So they are always being driven. Same can be said about a solid and a conventional jacketed bullet.
We all know that a barrel with a non uniform twist or a negative twist which is common with button rifled barrels does effect negatively on accuracy. So in that regards a GT will never hurt you from what I have seen.
Is it for everyone? Probably not. Is the costs difference depending on what you want…can it be justified? Maybe and maybe not. I’ll say it depends on what your doing with the rifle.
Me being a left handed shooter…and jacketed bullets…I’ll use the right hand twist rifling. I’ve noticed shooting a 1917 Enfield in 30-06 (those are 5 groove and left hand twist just like the British 303 Enfield rifles are all left hand twist) and shooting a 1903 Springfield which is right hand twist…I can tell how each rifle either torques into my cheek and how the other torques away from me. Being a lefty the left hand twist rifle torqued away from me. The 03 Springfield torqued into me.
Yes spin drift is different from a right to a left twist barrel.
To another comment made in this thread…I’ll also say…know your rifle! Practice and reading the wind cannot be substituted as well.
Later, Frank
Bartlein Barrels
Remember back in the hey day of schuetzenfest shooting/rifles….Off hand rifles had a weight limit of 10.5# if I recall correctly. An average caliber was .38 and .40 caliber. Later on .32 and even .28cal. The average bullet weight of a .40 was 330gr.
Pope would only make LH twist barrels. He said all the south paw shooters could suffer. Think of those heavy bullets and being a right handed shooter in a light weight rifle. That was one of the things he always said, “it helped the shooter control the rifle better.“
He also stated that the GT helped reduce fouling (remember these are lead bullets these guys are shooting) and that the bullet started easier into the rifling. I’ve got his book and actual word for word comments at work and I can post them on Monday if you like.
I just recently sold a Marlin Ballard #4 variation Rigby Ballard offhand rifle that Pope converted to 22rf. The barrel had 8 grooves, left hand twist and was a gain twist. From what I could measure I would say it was a 18 to a 16.5 twist. The bore condition of the rifle was flat out mint and it was made around 1905.
Steve Garbe asked me if he could put the rifle into a Pope machine rest that he had (gun was sent to him to repair the original broken stock) and shoot it. I told him to knock himself out. That gun shot 10 shot groups in the low .3xx’s at 65 yards outside. Wasn’t shot in a indoor range. Even new guns made now a days would have a tough time beating that. A action/rifle made in the late 1800’s (think it was around 1885ish) and a barrel made well over a 100 years ago.
I’ll post a picture of the rifle on Monday. I’ve posted it before on the hide somewhere.
My personal opinion is the GT and direction of the twist can help you with the bigger heavier bullets/more recoil type guns.
As Lowlight has stated and in the case of the 22rf I just pointed out…it’s not hurting you at all. That’s for sure.
All of my personal RF barrels are gain twist. Those soft lead bullets….the gain twist is always putting a fresh bite on them as they go down the bore. So they are always being driven. Same can be said about a solid and a conventional jacketed bullet.
We all know that a barrel with a non uniform twist or a negative twist which is common with button rifled barrels does effect negatively on accuracy. So in that regards a GT will never hurt you from what I have seen.
Is it for everyone? Probably not. Is the costs difference depending on what you want…can it be justified? Maybe and maybe not. I’ll say it depends on what your doing with the rifle.
Me being a left handed shooter…and jacketed bullets…I’ll use the right hand twist rifling. I’ve noticed shooting a 1917 Enfield in 30-06 (those are 5 groove and left hand twist just like the British 303 Enfield rifles are all left hand twist) and shooting a 1903 Springfield which is right hand twist…I can tell how each rifle either torques into my cheek and how the other torques away from me. Being a lefty the left hand twist rifle torqued away from me. The 03 Springfield torqued into me.
Yes spin drift is different from a right to a left twist barrel.
To another comment made in this thread…I’ll also say…know your rifle! Practice and reading the wind cannot be substituted as well.
Later, Frank
Bartlein Barrels
left hand gain twist barrels on my 6.5SLR and have a carbon fiber one ordered for my Creed hunting rifle. I will not buy another barrel that’s not a gain twist.
Q.) What are the benefits of the gain twist type rifling? A. I'll quote what Pope (Pope was one of the great barrel makers from a bygone era. His barrels along with Schalk who he learned from and gives credit to and Schoyen, and Zischang made barrels for the Schutzenfest type of guns/shooting in the late 1800's to early 1900's) said around a 100 years ago first. "The advantages of the gain twist are three. 1st The twist being less at the breech, gives less friction to the bullet; it there fore starts easier and quicker, giving the powder less time to burn on in front of the chamber, which there fore fouls less than in a barrel of uniform twist at the same necessary muzzle pitch (twist). nd 2 The slight change in angle of the rifling, in connection with choke bore (lapping choke into the bore of the barrel), effectually shuts off any gas escape of gas and prevents gas cutting, which is another case of rd imperfect delivery. 3 It holds a muzzle loaded bullet in position much better than a uniform twist .... Now I will add some more to this. First off I feel this applies more to a lead bullet shooter than a jacketed bullet shooter but some of the why's and why nots do over lap. With a gain twist barrel the bullet cannot go to sleep. The rifling is always putting a fresh bite on the bullet as it goes down the bore of the barrel. This is why I always go back to a cut barrel being better than a button barrel. A cut barrel even with a straight twist is more uniform and consistent than a button barrel. With button rifling the button can hit a hard spot/soft spot in the steel and it will slow the button down. The button could speed back up and do the twist it's suppose to be doing but either way you end up with a non uniform twist and if the twist keeps getting slower towards the muzzle these two things are a accuracy killer and lead consistency problems/fliers etc ..•1 feel even a slight gain twist will help accuracy wise and not hurt a jacketed bullet shooter as well. For the most part I would say there is no velocity gain in a gain twist barrel with the same load. What has been conveyed to us and it goes back to Popes 1 st point is that shooters have noticed that they can run a slightly heavier powder charge vs. a shooter with a straight twist barrel. As the bullet is starting easier into the rifling my only guess is the pressure isn't spiking as fast or is delaying the pressure curve. Hence forth they can get more velocity out of the gain twist barrel. I feel pressure is pressure and that the twist doesn't have anything to do with pressure for the most part but my only guess is that the gain twist like I said earlier is delaying the pressure curve. So you don't see problems as early like hard bolt lift etc... Also it's noted that even nowadays our military in some 20mm and the 30mm barrels like on the A10 Warthog ground attack aircraft have gain twist type rifling in the barrels.
Attachments
Above is the pic of the Ballard with the Pope GT type barrel. 8 grooves and left hand twist.
Also above are some quotes from Pope on GT and my thoughts about it as well. Wrote that up a while ago.
Attached here is spin drift. This is probably a little over exaggerated but should get the point across.
Later, Frank
Also above are some quotes from Pope on GT and my thoughts about it as well. Wrote that up a while ago.
Attached here is spin drift. This is probably a little over exaggerated but should get the point across.
Later, Frank
Except... that's not really what you're seeing (torque)... Shoot a handgun with your right hand - the gun will track up and to the left, away from your hand. Shoot a handgun with your left hand - the gun will track up and to the right, again, away from your hand. If that was the result of torque (from the bullet acting against the rifling), the gun would recoil in the same direction regardless of which hand it was in. What you're actually seeing is lack of support in the direction that the gun moves - it parallels what Lowlight talks about, where recoil will always find the weakest path behind the rifle. Same goes for handgun.
Back in the day, Schuemann made a variety of interesting rifling configurations for .38 Super / 9mm USPSA Open guns, including 1:32 twist barrels, and super radical gain twist barrels (literally 0-16 twist - at the chamber, the rifling started straight down the bore). Normal barrels for those calibers are 1:16. Even at half the twist (and half the torque), or with a super gradual spin up (in the GT configuration), the gun still recoiled away from the hand just the same - and there was minimal noticeable effect to recoil behind the gun.
Torque does play a small role in the recoil profile on a handgun, but it's not what you think, and not what you're seeing shooting one handed...
I have a Tika set up as a switch barrel. I have four barrels for it.proof carbon 308, original factory 6.5 CM, Left hand game twist Bartlein 6.5 CM, and proof carbon 6.5 PRC.
set up for field shooting/hunting the gun is 14 pounds, depending on which barrel is on it I can add a bit of weight so it balances and weighs the same. my experience is that the left hand gain twist barrel is more forgiving for load development, more forgiving of slight inaccuracies when reloading, when shooting from field positions unsupported it’s easier to stay on target during follow through. Recoil pulse feels more linear and less sharp. all of this creates a greater sense of confidence when shooting the left hand gain twist. The small mechanical advantage and increased sense of confidence combined to improve my hit percentage with that barrel on the gun.
if available as an option when replacing a barrel I will always go left hand gain twist in the future.
set up for field shooting/hunting the gun is 14 pounds, depending on which barrel is on it I can add a bit of weight so it balances and weighs the same. my experience is that the left hand gain twist barrel is more forgiving for load development, more forgiving of slight inaccuracies when reloading, when shooting from field positions unsupported it’s easier to stay on target during follow through. Recoil pulse feels more linear and less sharp. all of this creates a greater sense of confidence when shooting the left hand gain twist. The small mechanical advantage and increased sense of confidence combined to improve my hit percentage with that barrel on the gun.
if available as an option when replacing a barrel I will always go left hand gain twist in the future.
Finally have a LHGT threaded up! Can’t wait to see how it shoots, which requires… ammo. Terrible inconvenience, really.
Bartlein MOD400BB, 28”, 1:8.5-1:7.5, M24ish profile plus the @LongRifles Inc. Pattern X fluting. The entire rifle weighs in at 9.5lb, compared to 8.8lb with the Proof savage prefit that lasted ~1500 rounds.
Bartlein MOD400BB, 28”, 1:8.5-1:7.5, M24ish profile plus the @LongRifles Inc. Pattern X fluting. The entire rifle weighs in at 9.5lb, compared to 8.8lb with the Proof savage prefit that lasted ~1500 rounds.
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