Tensioned barrel systems work?

[thammer]

Here is a Kral Pro500 setup for benchrest competition I tuned. Un-regulated shooting 60fpe in 25cal with JSB 33.95 MKII Heavies. has an internal barrel tensioning system using 1/8" walled 1" OD 6061-t6 aluminum tubing inside the factory shroud. Almost zero recoil or barrel vibration during the firing cycle. Let me know if your rifle can do this and what barrel setup it uses so we can all learn more about what works. 





https://youtu.be/D6hBUwOZxbE

 

[Eaglehorn]

Following this thread.

There's a mod Ernest has been showcasing for FX guns with a carbon fiber sleeve that goes over the barrel and tensions it between the shroud or moderator. Curious to hear from others using a tensioned barrel system vs pure free-floating barrel.

 

[Removed]

Nothing new here, a true tensioned barrel is way to go. You see this with some of the custom guns Doug Noble builds as well as factory hardware on American Air Arms rifles. I'm surprised more companies aren't following this type of design. Less vibration, less harmonics and just an overall more solid way to match a barrel. 

 

[JamesD.]

Tensioned barrels are definitely needed for any system that has barrel mated to receiver weakly, or in interchangeable systems like FX liners.
They weren't really looked at until we started pushing heavy pellets and slugs from our pellet guns. As power increased, so did harmonics.

The best example I can think of is the .257 Scandalous I opted to buy. It's by far the best rock solid platform I found. Not saying others aren't good but this one proved to print 1/8" moa groups while tethered consistently. 
It achieved this by utilizing a good solid SS Lilja bull barrel threaded at 72tpi 3.5" into a solid mono block. 
It doesn't need a tensioned shroud. In fact I'm not sure one could improve this well thought out design. I definitely wouldn't mind a functional shroud though as it's already a full sized rifle.

 

[JohnnyPDX]

If I understand 'tensioned barrel' correctly then my Artemis PP700SA is a tensioned barrel system.

 

[JamesD.]

Nothing new here, a true tensioned barrel is way to go. You see this with some of the custom guns Doug Noble builds as well as factory hardware on American Air Arms rifles. I'm surprised more companies aren't following this type of design. Less vibration, less harmonics and just an overall more solid way to match a barrel.

I'm not saying you aren't right. Believe me, I like Doug. But he is utilizing a platform that allows big lead at high power. It's highly improved but based off a Condor design. Not from the ground up. Doug could make anything he puts his mind to. It all depends on what we want to shoot and at what power.
The OP is utilizing 33.95's at 60fpe from a rifle that was designed as a pellet shooter. That's not really asking too much from it so I expect we see great results from the tensioned shroud. 
Basically I guess I'm saying a great pellet gun that's a dedicated caliber shouldn't need a tensioned shroud but if we try slugs? Some are definitely in need if more is going to be asked of it. 
This all ties in with Diabolos are self stabilized, slugs aren't & the heavier slugs add resistance which in turn changes the harmonics. So yes a tensioned shroud can be a great answer. 
I just don't want anyone thinking that a gun might be sub par if it doesn't have, a tensioned shroud. 


https://www.shootingsoftware.com/barrel.htm

 

[Vetmx]

If I understand 'tensioned barrel' correctly then my Artemis PP700SA is a tensioned barrel system.

Yes and that’s why the little turd is so accurate. I built several LW barrels for mine. Didn’t want to go the extra step threading to tension them. But I had to. There was enough of a difference that the one extra step was worth it.

 

[elh0102]

A tensioned barrel system is A system, not THE system. Accuracy demands the barrel to be in the same place with each shot, and behave the same way harmonically. There are good and weak tensioned systems, just as any other. As a point of interest, if you review high level benchrest results, you will find very few tensioned systems. 

 

[Vetmx]

I tensioned the barrel on my Impact within an hour of opening the box it came in. The little white dots are so I can put the exact same tension on it every time I take it apart for cleaning. Change the tension change the tune and I don’t want that. I will clean up the design if I am satisfied with the results.

 

[Arzrover]

Seems like we're missing the point on the tensioning idea...... weight. A heavy bull barrel is going to be the best at controlling harmonics in all conditions. Elh0102 is correct that you will mostly not see tensioned barrels in competition unless they are trying to make a weight goal. Tensioning will raise the harmonic frequency and lower the amplitude just like going to a heavier barrel... but way less weight. The main problem with the system is temperature. If your shroud is a different material than the barrel, they expand at different rates and the tension changes. This can be controlled and there are several successful methods, but just randomly tensioning a barrel is likely to create "good" and "bad" temperatures for accurate shooting .

I DO like the tensioning system on the EVOL, but he is trying to save weight everywhere on it while still offering a very robust rifle. Could it shoot more accurately with a heavy barrel? That would be difficult, but I think so. Am I going to do it... absolutely not. It's a GREAT package as designed. 

My $0.02.

Bob

 

[qball]

Seems like we're missing the point on the tensioning idea...... weight. A heavy bull barrel is going to be the best at controlling harmonics in all conditions. Elh0102 is correct that you will mostly not see tensioned barrels in competition unless they are trying to make a weight goal. Tensioning will raise the harmonic frequency and lower the amplitude just like going to a heavier barrel... but way less weight. The main problem with the system is temperature. If your shroud is a different material than the barrel, they expand at different rates and the tension changes. This can be controlled and there are several successful methods, but just randomly tensioning a barrel is likely to create "good" and "bad" temperatures for accurate shooting .

I DO like the tensioning system on the EVOL, but he is trying to save weight everywhere on it while still offering a very robust rifle. Could it shoot more accurately with a heavy barrel? That would be difficult, but I think so. Am I going to do it... absolutely not. It's a GREAT package as designed. 

My $0.02.

Bob

Great point on the temperature. Maybe the tensioning idea isn't quiet as great but I haven't see any noticeable change in POI with temp change. In theory if the sun heats up the shroud it could change POI, my question is how much tension is needed to mitigate the temperature effect or if it could be mitigated. I'm using carbon tubes which supposedly are pretty stable in terms of expansion, I'm thinking as long as the tension is even around the barrel there might not be noticeable accuracy change? How to prove or measure that theory is fascinating. However I still would prefer having slight variation in tension as supposed to no tension because the harmonic problem on 700mm FX liner system is rather big! 

 

[JohnnyPDX]

If I understand 'tensioned barrel' correctly then my Artemis PP700SA is a tensioned barrel system.

Yes and that’s why the little turd is so accurate. I built several LW barrels for mine. Didn’t want to go the extra step threading to tension them. But I had to. There was enough of a difference that the one extra step was worth it.

Mine turd shoots quite well and clearly responds to tensioning as seen in POI.

 

[vmaxpro]

I shoot a tension system on my uragan. 6061-t6 1.25x.083 shroud over a .562 35” barrel. Took a few tries to get it right but shooting from 90f to 40f no noticable change. You can use spring washers or not. I dont, the key is the amount if torque.

 

[Dairyboy]

I find the EVOL system to be superior to any other system seen. Like Bob stated though could you use a barrel the same size as the barrel system and not need to worry about harmonics? Likely so but then it'd be very heavy.

 

[thammer]

Who's tried balancing a pellet on the barrel/ shroud while firing with their rifle?