tacom structured barrel
- Thread starter Guan999
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I understand the ballistics of the bullets hitting the same point of aim. That's not the engineering of a structured barrel. And if it was something to do with harmonics I would need to see how that works like with the above slow motion camera. Cause I would think a straight 1.2" tube would have minimal harmonic deviation. But I'm not going into that abyss.
The basis is the harmonics and a few small other things. It is well known that a straight barrel tend to whip less. What they have done to what in reality is a straight profile barrel is to block the path of the barrel’s harmonics. They flute and drill based on computer simulations of the barrel’s harmonics. They are also changing the cooling thermodynamics reaction of the barrel. As I have said a few times I understand the Engineering of the idea. What I am unconvinced about ( due to the incomplete test protocols) is to what extent they are actually making meaningful change.
If is interesting that the new Noveske DDF series of barrels is claiming the same benefits. They have used a different easier path , no holes but deep rounded flutes, to gain the same results. This in principle should gain some of the desired outcomes with the ability to built at rate.
I am still interested, not enough to buy one, but interested nonetheless. I am waiting for more concrete studies and victory plaque evidence. But as always I love true innovation.
If is interesting that the new Noveske DDF series of barrels is claiming the same benefits. They have used a different easier path , no holes but deep rounded flutes, to gain the same results. This in principle should gain some of the desired outcomes with the ability to built at rate.
I am still interested, not enough to buy one, but interested nonetheless. I am waiting for more concrete studies and victory plaque evidence. But as always I love true innovation.
I have read through this thread.
Since I do have a degree and have been through a few quantum physics classes, thought I could add some info.
From what I have seen over the years with long range shots using standard type of barrel and very specific ammo, the barrel harmonics are usually dampened with one or more weights on the barrel. Barrels "bend like rubber" when a round goes through them. It's physics.
The structured barrel design is interesting. It appears to have natural damping across a wide range of rounds, hence why Tacom says the rifle shoots the same regardless of the ammo used. Their design appears to be a closed star pattern, basically a tube that has parallel bore ribs to provide anti-bending, and then it's closed which makes it even more stiff and forms cooling channels. The ribs on this example provides lots of strength from bending, in other words, the bending moment parameters change and the harmonics from the round are squashed. So what Tacom is doing is manipulating characteristics via physics. Neat.
Since I do have a degree and have been through a few quantum physics classes, thought I could add some info.
From what I have seen over the years with long range shots using standard type of barrel and very specific ammo, the barrel harmonics are usually dampened with one or more weights on the barrel. Barrels "bend like rubber" when a round goes through them. It's physics.
The structured barrel design is interesting. It appears to have natural damping across a wide range of rounds, hence why Tacom says the rifle shoots the same regardless of the ammo used. Their design appears to be a closed star pattern, basically a tube that has parallel bore ribs to provide anti-bending, and then it's closed which makes it even more stiff and forms cooling channels. The ribs on this example provides lots of strength from bending, in other words, the bending moment parameters change and the harmonics from the round are squashed. So what Tacom is doing is manipulating characteristics via physics. Neat.
Agreed, I also have a degree
. I just want public proof. I think I said about the same further up. Some barrels I have seen pictures of also have holes drilled in various directions. The combination serves to block the propagation of harmonics. I think the Noveske DDF will accomplish much of this same principle at a much reduced price.
. I just want public proof. I think I said about the same further up. Some barrels I have seen pictures of also have holes drilled in various directions. The combination serves to block the propagation of harmonics. I think the Noveske DDF will accomplish much of this same principle at a much reduced price.Harmonics is such a handy word when it comes to centerfire barrels. If someone uses it unironically you know they don't know what they're talking about.
It's more correct to think of the barrel being cracked like a whip. With that physical model it makes a lot of sense for a structured barrel to have a smaller shift in POI between loads. The structured barrel is going to have a much higher moment of inertia relative to a solid barrel of the same mass and that moment of inertia is going to directly resist that "cracking" (bending) motion induced by firing. That resistance to bending will then lead to a smaller delta in response to an equal spread in inputs.
It's more correct to think of the barrel being cracked like a whip. With that physical model it makes a lot of sense for a structured barrel to have a smaller shift in POI between loads. The structured barrel is going to have a much higher moment of inertia relative to a solid barrel of the same mass and that moment of inertia is going to directly resist that "cracking" (bending) motion induced by firing. That resistance to bending will then lead to a smaller delta in response to an equal spread in inputs.
Is the displacement from the barrel movement purely in the vertical y-axis (that it's also simplified to), or is there movement/displacement in the x and z axis as well (like a cork screw/helical motion)?
There will be some movement in a both the X and y axis not sure how it grows in in length ( it could maybe, never seen that modeled). When I used the word harmonics I was generalizing the vibrations and movements that are the result expanding gas, torsional friction of the gas and bullet traveling down a spiral path and the effects of the accerating mass. Add in internal stress points that interrupt the predicted vibration or “whip” path. The structured barrel seems to be trying to create a “Dead” tube. Not sure how well that actually works because the energy has to go somewhere.
Yep, the barrel whips in X-Y plane, and, it also get's bigger and smaller in the Z axis (axial) from bullet friction against the grooving. However, try compressing a short length of steel rod, then try aluminum. It will compress, but not by much. A really long rod will appear to compress at a higher rate than a short length, that's because the longer it is the more it will bend (bow). "long" rods and tubes are are very strong on axial, long lengths of flats are much stronger on short edge. Anyways, I think the structured barrel is neat.
As far as I can tell, the Litz video that @Csafisher posted (of a sporter weight Remington 700) shows absolutely no barrel whip at the muzzle. The barrel appears to move straight back.
Are you guys all saying that the harmonic whipping of the barrel you're referring to is so small as to be invisible on high speed video?
Are you guys all saying that the harmonic whipping of the barrel you're referring to is so small as to be invisible on high speed video?
the other thing to notice how much the rifle moves rearward before the bullet exits.
It's not harmonic, and yes it's smaller than you will resolve on most HSV.
Without knowing full details of the camera setup I can't say for certain, but .004 inches/pixel is probably in the ballpark. The lateral barrel motion would be in the neighborhood of .006", so a single pixel shift.
Litz is entirely right about the rearward movement and its interaction with the shooter and rest being far more significant.
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Anything to get that bullet put to sleep, man. Rowdy.
I can't tell in any video i have seen if the barrel is wiggling .003-.006" or the thickness of one to two sheets of paper. I know when I try to look at something that small I genrally need a microscope though.
That’s because tuners don’t do what they “think they do”.
Something may change and prob does but it’s not the magical wet noodle flopping around becoming a stable consistent movement all of a sudden
As a consideration... Does anyone know what/ how the naval guns (or tank) sort this out? Relatively speaking, they appear to have quite good accuracy, and from a bore to diameter ratio, they wouldn't scale to a typical heavy barrel
All I know is I haven’t seen any 100lb tuners on the end of a tank barrel….
From my extremely limited artillery experience (I rode by them and gave them the finger a lot), I understand that they actually weighed sorted the projectiles/rounds to match up to the charges. I'm pretty sure the naval guns did that too. Don't forget that they get a "box" to impact in (one square kilometer...so 500 meters of leeway on either side). And yes, I've been there when they went out of the box too. That kind of stuff gets one of those guys fired. Had naval gunnery go so far out of the box one day that we were pretty sure that they were trying for us on the G-3 range on LeJeune. In typical fashion, about 3 minutes after the ground shook we got a call over the radio to take cover because somebody out at sea let one go just a tad looooong.
As far as tanks go, well, the accuracy is pretty decent all things considered. Some systems are definitely going to be more accurate than others, but you are still in the general ballpark of about 10 MOA if they were to try to shoot at the same target a few times. I don't have a ton of tank experience either...but I used to ride past them a lot and give them the finger too...
