Tanio Koba TWIST Inner Barrels.

[ILLusion]

After years of hearing and reading endless debates about Tanio Koba Twist inner barrels, and after years of hunting for them, I've finally acquired a couple of them in various lengths for various guns from AEGs to GBBs.

Here are my initial findings:

These inner barrels shoot STRAIGHT. They have an extremely predictable, flat and straight flight trajectory. Where standard hop up will cause the BB to gently curve up before dropping, TWIST (or cyclone) inner barrels will cause the BB to go extremely straight for an even further effective range before dropping.

To set a clear and definitive answer for all the debates that have floated on the internet for years:

Q1. "How is it physically possible to have a rifled barrel impart a spin on the BB and combine it with the Magnus effect of the hop-up? It is two totally different axes of rotation!"
A1. Actually, the barrel ISN'T "rifled" in the standard sense of a real gun. Yes, the inner barrel has spiral rifling grooves in it, but the BB does NOT touch the groove. The purpose of the TWIST inner barrel is not to put a rifling spin on the BB. It is to put a "cyclone" of air around the BB, to help float it through the inner barrel and PREVENT the BB from touching the side walls of the inner barrel at all. The result of this is higher accuracy, more predictable trajectory and greater effective range.

Q2. "I've heard about power requirements for these inner barrels. Details?"
A2. What you've heard is true. The twist inside these inner barrels are optimized for guns that shoot NO MORE than 1 Joule or 330fps with 0.20g BBs. Some internet debates claim that if you have a higher powered gun, all you need to do is use heavier BBs to slow down the velocity of the shot. NOT TRUE. The air moving around the BB will still be beyond 1 Joule and it will affect the shot trajectory.

Q3. "What happens beyond 1 Joule or 330fps with 0.20g BBs?"
A3. Up to 330fps, the results of the shot and even the shots dropoff are very predictable, accurate and flat. Groupings remain tight with very little spread. However, once the velocity of the shot begins to exceed that limit, the shot starts to become unpredictable with increased spread. The higher the velocity, the greater the perceived spread.

Q4. "So how accurate are these inner barrels compared to other brands such as Prometheus, KM TN or Systema?"
A4. At this time, I have not done any quantitative comparitive range testing to get accuracy results. When used within its optimized power range, I can outright say that these inner barrels have a MUCH straighter trajectory, greater effective range and a generally much more predictive flight path than any other barrel I've used before.

There is a project underway for an indoor range test to compare various lengths of these barrels against other barrels at different power ratings (stock, 1Joule and 400+fps).

How do I like these inner barrels? I love them. I wish they worked well at 400fps. At 360fps, they are still very acceptable and I will take that in to consideration when using them in some of my guns.
But for now, I am FOR SURE putting these inner barrels into all my pistols and low powered AEGs.

Further questions? Comments? Post away!

[gandar]

How does the range compare with a 1J gun with a Twist barrel, vs. a higher powered gun with a standard tightbore? I've seen people say that a lower powered gun with the proper accuracy upgrades will outshoot a higher velocity gun with a standard barrel, does this out perform a higher powered gun with a tightbore? You say the trajectory is flatter, and more predictable, does this also translate into better *effective* range?

[ILLusion]

Of course. As mentioned, the effective range is much further than standard hop up on a tightbore.

I'll have to let you know how range compares in a 1J Twist setup versus a high powered tightbore setup.

The statement where "a lower powered gun with the proper accuracy upgrades will outshoot a higher velocity gun with a standard barrel"... is that referring to range only? It's been proven that the higher you increase the velocity of your gun, the greater your shot consistency will spread. Especially if you are using the same weight BBs. It will cost an exponentially larger sum of money to tighten the shot spread to within the range of a properly upgraded low velocity gun. Light weight BBs have a greater tendency to not shoot straight when shot at high velocity.

If it's regarding range only, I believe that statement is false. There's only so far a BB can go before you need extra power to push it further.

[gandar]

Yes, I suppose that refers to shot consistancy, so thanks for clearing it up.

But I am definately still interested in seeing the results between a 1J Twist set up vs. a high powered tight bore. That could definately prove interesting, considering the strain high powered rifles can put on the mechbox (particularly V2). If you could get the same results from a lower velocity rifle, and save the strain on your mech box, that'd be awesome.

[Dracheous]

All I can figure about these "Twisted" or "rifled" barrels is that it doesn't make sense to me. The BB's we use are hard plastic, not soft enough to be shaped by the rifling. Nor do I see how this can give/get any better spin to the round than the hop up systems in AEG's presently. The overhead wheel puts a nice back spin, which because its a sphere really works well. Now if they divited the rounds like a golf ball than we'd see some improvement. But who wants to pay EVEN more for a hand full of live savers :P



Its like the difference between my MP4 and my M4A1. My M4 has great velocity and a decent grouping, but the MP5 will get better range ((Not accurate range but better range)) however in the brush the slightest/tinest branch kills the MP5 rounds where as the M4's cut through better. The only thing that I can think of to cause this would be that the slower moving MP5 round ((Also note these are both firing 0.25)) has a more stable back spin on it, but has not momentum behind it to punch through the brush. Where as the M4 has so much more air pressing the round forward that it has lots of momentum but because of the increased velocity resulting in a more instable spin to the round.

It'd be interesting to see what these barrels did with a softer round though

[Cheesevillage]

Deacheous the "rifling" doesn't even touch the BB. Air moves up the rifled shafts and keeps even pressure on all sides of the BB, thus reducing friction inside the barrel because the BB "floats" as opposed to bounces.


-Cheese

[ILLusion]

Originally Posted by Dracheous

All I can figure about these "Twisted" or "rifled" barrels is that it doesn't make sense to me. The BB's we use are hard plastic, not soft enough to be shaped by the rifling. Nor do I see how this can give/get any better spin to the round than the hop up systems in AEG's presently. The overhead wheel puts a nice back spin, which because its a sphere really works well. Now if they divited the rounds like a golf ball than we'd see some improvement. But who wants to pay EVEN more for a hand full of live savers :P

Originally Posted by Cheesevillage

Deacheous the "rifling" doesn't even touch the BB. Air moves up the rifled shafts and keeps even pressure on all sides of the BB, thus reducing friction inside the barrel because the BB "floats" as opposed to bounces.

Exactly.

Originally Posted by ILLusion

Q1. "How is it physically possible to have a rifled barrel impart a spin on the BB and combine it with the Magnus effect of the hop-up? It is two totally different axes of rotation!"
A1. Actually, the barrel ISN'T "rifled" in the standard sense of a real gun. Yes, the inner barrel has spiral rifling grooves in it, but the BB does NOT touch the groove. The purpose of the TWIST inner barrel is not to put a rifling spin on the BB. It is to put a "cyclone" of air around the BB, to help float it through the inner barrel and PREVENT the BB from touching the side walls of the inner barrel at all. The result of this is higher accuracy, more predictable trajectory and greater effective range.

[CDN_Stalker]

Too bad these things can't work on sniper rifles up to 500fps, I'd love to get one for my M24! Then again, maybe with heavier ammo, they might work alright?

[Kid]

The twist inside these inner barrels are optimized for guns that shoot NO MORE than 1 Joule or 330fps with 0.20g BBs. Some internet debates claim that if you have a higher powered gun, all you need to do is use heavier BBs to slow down the velocity of the shot. NOT TRUE.

;-)

[Vivisector]

These things would have the opposite effect on FPS than a tightbore, wouldn't they? I mean, more air is getting past the BB and all...

[CDN_Stalker]

Originally Posted by Kid

;-)

Point, but counter point, wasn't talking about using a heavy BB to slow down the velocity, was talking about the stability of the heavier round, and mainly the comparison of tightbore vs. twisted barrel, at those velocities with heavier rounds, would the twisted barrel shoot a lot worse than a tightbore (ahem, or even a stock barrel). Have to wait and see what Illusion comes up with using the barrel in hot guns, and most likely he'll test with a range of ammo for a broad range of results in different conditions.

[gandar]

I wonder how difficult it would be to produce a tightbore version of a Twist barrel... Or if it would work, for that matter. One would think, that since the detrimental part of higher velocities is that the air goes past the BB too much, if you were to reduce the size of the barrel, you would theoretically reduce the air going by the BB because there'd be less room for it to go past.

[Dracheous]

that would nulify the point behind the twist, and then you get into why I thought this was non-sense. The twist is supposed to make a cushion of air around the bb as it travels down the barrel ((didn't see that point made before there Illusion)). If the bb is in constant contact with the twist/rifling then you have the issue like I said, the round is too hard, not soft enough to let the rifling work. You'd just have a bb corkscrewing down the barrel and fly off in random directions out the barrel ((Like a shot gun)).

[gandar]

....You're still missing it. A tightbore doesn't touch the BB either. If you could use a tightbore Twist barrel, you wouldn't be spinning the BB (still) you would just be creating a smaller space AROUND the BB for the air to go past, which seems to be where the problem is when using higher velocities in the Twist barrels.

[ILLusion]

Originally Posted by Vivisector

These things would have the opposite effect on FPS than a tightbore, wouldn't they? I mean, more air is getting past the BB and all...

When comparing velocity to a Prometheus 6.03mm inner barrel in a 400fps M14, the TWIST inner barrel was only about 5fps less on average, showing that they are still tighter than stock inner barrels.

Originally Posted by CDN_Stalker

Point, but counter point, wasn't talking about using a heavy BB to slow down the velocity, was talking about the stability of the heavier round, and mainly the comparison of tightbore vs. twisted barrel, at those velocities with heavier rounds, would the twisted barrel shoot a lot worse than a tightbore (ahem, or even a stock barrel). Have to wait and see what Illusion comes up with using the barrel in hot guns, and most likely he'll test with a range of ammo for a broad range of results in different conditions.

It doesn't seem to matter if heavier BBs are used. At high velocities, the BBs just seem to fly everywhere at the end of their range (powered by the gun's initial energy, and not from Magnus effect), and I'm thinking it may be because the TWIST inner barrel does put some kind of gyro spin on the BB.
Further testing is required to verify this information.

Originally Posted by gandar

....You're still missing it. A tightbore doesn't touch the BB either. If you could use a tightbore Twist barrel, you wouldn't be spinning the BB (still) you would just be creating a smaller space AROUND the BB for the air to go past, which seems to be where the problem is when using higher velocities in the Twist barrels.

That statement contradicts two of Japan's oldest airsoft manufacturers. Both Systema and Tanio Kobayashi claim that BBs DO bounce around inside an inner barrel. Systema claims that BBs have a tendency to bounce around an inner barrel even more when the bore is tighter, and which is why they stick to a 6.04mm process and won't go tighter.

This is a good read: http://www.systema-engineering.com/E...unchiku3-1.htm

Of course, there is no substantial evidence to verify any of these claims.
Range tests need to be performed to verify.