Tanio Koba TWIST Inner Barrels.

[The Saint]

Update, finally got fed up with fiddling around with my Firefly bucking in my P229, switched to a stock TM bucking. Hopup no longer needs to be dialed to maximum to get proper hop, now it shoots straight at about 45%. Setting it to 100% causes the BB to go straight up after about 40'.

[bearded-gelfling]

I was wondering how much does the length of a twist barrel improve accuracy and range? Or is it like a smooth bore barrels; the length not make much difference unless you significantly lengthen the barrel.

I'm looking to put a twist barrel in my JG G36C and was thinking of extending the barrel and using a suppressor to hide the extension. My JG out of the box clock 335 fps or there about, so is perfect for the twist barrel.

But having done some research I found out that going from a 247mm smooth barrel to a 363mm smooth barrel wont improve my range or accuracy that much; its the tightness that improves this, from what I’ve read.

Also upgrading my hop from the stock JG one will make a big difference, as by all accounts the JG ones are useless. But now having seen these twists barrels it looks like I might be able to kill two birds with one stone. Extend my barrel and improve accuracy; with out having to buy a replacement hop to go with the tight bore barrel. Or whould you still suggest repalcing the JG Hop?

[Phil_Black]

I dont know were you have research this but it's wrong.

If you hit a target let's say 10cm X 10cm at 80 feets with a stock inner barrel at 247mm you get a grouping of 10X10.

By replacing it with a tight bore (6.04) you will hit the same target at a much smaller grouping lets say 4X4cm

So at 100 feets you now have a grouping of 10X10

So in total you gain 20 feet of range and improove your accuracy.

Theses numbers are just to show you how it works.

So going to a 363 mm inner barrel sill do the same but in it's stock form it still got more range. So does a 510 mm inner Barrel.

Up grading ths hop up sleeve is the thing you have to do. Get yourself a nice promoteus blue/purple soft type. This will be the combo so you will see the big difference.

Adding a twist barrel will give you moore accuracy by getting the same trajectory on the BB's each time (at least that'S what i get from my part)

[bearded-gelfling]

I was informed by a guy that works at Airsoft World (UK Scottish based company) advised me that I'd be better off with a good Hop Up and tight bore barrel mod over anything else. He seemed to be quite adamant that a longer barrel will not greatly improve my accuracy when hitting a man sized target, compared to the cost of such a mod.

He basically said that any difference I’d notice would be negligible in something like a G36C even with a longer barrel hidden with a silencer. He said unless you where talking expensive bolt action snipers the barrel length really did make much of a difference. He also seemed to advice me to go for a Systema tight bore barrel over the Mad Ball’s his shop sold; so sort of made me think he probably giving me sound advice from his perspective, rather than trying to do a sales pitch on me for something more expensive.

I can see what your saying but when I’m using a carbine assault rifle all I need to be able to hit is a man sized target the size of the grouping is not that much of an issue especially if we talking cm difference if it was more like inches coming onto feet then it would make sense for me to upgrade the length. But for the guns use; CQB and woodland fighting, it seems like over kill and a waste of money. I'm only a poorly paid ICT tech in a Gov funded school.

[krap101]

I talked to a really smart Aerospace PhD student (I'm a sophmore in aerospace), since I've been wanting a "scientific" answer for the aerodynamics of a twist barrel. He said that he believed that decreasing the turn rate of the spiral of the barrel wouldn't really affect the max fps of the barrel. I think it had something to do with the aerodynamics of a sphere, and something called the Karman vortex street. At a certain point, the velocity of the air will cause vortices to get thrown off unevenly, which will destabilize the bb.

http://en.wikipedia.org/wiki/K%C3%A1..._vortex_street

Although he wasn't 100%, and this isn't exactly his field, he's extremely smart, and I would side with him than just about anybody else.


Interesting video

YouTube - unstable velocity flow of air past cylinder with alternating direction

YouTube - karman vortex street

YouTube - Fluid Mechanics - Cool Science Experiment

[ibangkneebacks]

so this thread is for the disscussion on the pro's and cons of the TK twist barrel system...

lets please keep our inquiries and comments to a easy mannerism...in other words lets b nice =)

to krap101- yeah bro check out the vid on youtube called "Tanio Kobas Twist Barrel - Testing on an M14"...posted by a doof named 'd1ggah'...i'm jk about the doof part coz he did the vid on a whim and forgot to use a stand...so the grouping is a little off...
i have 5 barrels in use right now...one in my A&K SVD, one in my G&P SVD, one in both my TK KJW M4's and one in my Inokatsu...all have done the same; evened out the fps, made the trajectory straighter and my grouping is alot tighter...yet has compromised distance...this is okay for i am more into accuracy than power transfer...

also, i hope tokyoseven is nice and plays a little joke on my thread again =)

[ibangkneebacks]

oh yeah, thanks krap...also the spin is random...since the bb hop-up chamber causes a bb to 'backspin' most of the time, the difference in spin direction is greatly affected by the tight twist...the barrels come 6.03mm-6.01mm in tighness (i believe, it's been a while and i can't find these anymore)...if i had a highspeed cam i'd b able to explain more...most of this info was built upon hypothesis that has been somewhat proven...(by grouping and chrono...there is yet to be an advanced scientific experiment to elaborate on the specifics a little more)...

however, now there's a fun experiment for all you (me included lol) to try out...all u really need to do is set up a highspeed cam around the barrel and then draw the lines of refference onto the little bb's lol and the foreground of the highspeed cams shot...then it's simple math to figure out the speed and spin revolutions...the trajectory experiment will be alot easier...

[ibangkneebacks]

so would widening the grooves improve flight for a higher fps?...this is the only way i can think of that will possibly quash the fps limitation on the twists...so are my groupings accurate/is there something i missed thats causing the current grouping i am experiencing?...
my sheets are still tight @10yrds, a little loose @50 & a deffo knuckling @80 on the KJ M4..tho the off set isn't noticable frm where i am...i think i need to see it from the other end...
they make 50yrds good, after that with a high fps, they're shit...2-3" groupings @80 is way off for me...but i guess it's years of compensation, oddly shaped bb's, or i'm getting gusts of random wind from somewhere?...shit man please help...it's worked fine on my A&K is it possible that its the way i fit the inners?...my A&K has a wonkey inner set up...popsicled together...i chopped the hop-up off the original & tk, slid the orig & tk back in and used another piece of the original inner to complete the length...does this affect anything? did i fluke it?

[Azathoth]

On a AEG the TK barrel is no better or worse than any other 6.03mm barrel that I have used at any velocity range that I have played. that's 280fps low limit games up to hardball @600fps.

[ILLusion]

Originally Posted by ibangkneebacks

my A&K has a wonkey inner set up...popsicled together...i chopped the hop-up off the original & tk, slid the orig & tk back in and used another piece of the original inner to complete the length...does this affect anything? did i fluke it?

Unless you're some aerospace engineer working with NASA grade machine tools accurate to +/-0.0001mm and able to merge items to within that type of accuracy, I'd say you're screwing it up. The MOST important aspect to a precision barrel is surface consistency. A difference greater than +/-0.001mm will visibly affect shot accuracy, hence, the requirement to maintain a ten-thousandth of a mm to maintain that accuracy in surface consistency.

So did you affect anything? It's likely... but then again, I don't know how precise your methods are or what your mechanical skill and prowess is. Maybe you really are an aerospace machinist...


About 15 years ago, a company was machining add-on suppressors that had inner barrels integrated in to it. The idea, was a quickly extendable inner barrel, by screwing on the silencer. While the concept was unique and interesting, it failed miserably. It had been tried many times by individuals before, and after that, but ultimately, everybody's ended up with the same results. So, don't mind if we are skeptical of your hack job working successfully.

[DrSmashPanda]

Should I use a Nine ball 6.03 or TK twist for TM Glock 17 ?
shooting under 1J

[ILLusion]

I personally prefer Twist barrels for ALL of my guns in the <1J range.

[Dynamo]

Originally Posted by krap101

I talked to a really smart Aerospace PhD student (I'm a sophmore in aerospace), since I've been wanting a "scientific" answer for the aerodynamics of a twist barrel. He said that he believed that decreasing the turn rate of the spiral of the barrel wouldn't really affect the max fps of the barrel. I think it had something to do with the aerodynamics of a sphere, and something called the Karman vortex street. At a certain point, the velocity of the air will cause vortices to get thrown off unevenly, which will destabilize the bb.

http://en.wikipedia.org/wiki/K%C3%A1..._vortex_street

Although he wasn't 100%, and this isn't exactly his field, he's extremely smart, and I would side with him than just about anybody else.


Interesting video

YouTube - unstable velocity flow of air past cylinder with alternating direction

YouTube - karman vortex street

YouTube - Fluid Mechanics - Cool Science Experiment

interesting videos, unfortunately they don't really apply to a BB being propelled down a barrel. the gap between the BB and the barrel wall as well as the pressure differential between the air ahead of the BB and the air behind it pushing on it, as well as taking into account the BBs backspin are very important.