Tanio Koba, Hop Barrel Twist Test

[sgtHanzo]

Disclaimer: The resultS published here are not intended to be biased for or against the Tanio Koba barrel.

BASIC INFORMATION

 

AEG Tested: G&G Full Stock M16 A4

Spring: Systema M120

Battery: 12v, 3300Mah

Test Environment: Indoor

Distance Tested: 45ft.

Hop-up setting: No Hop-up

BB Used: 0.25g, AE Bio

 

AEG was fired while on top of a table supported by a Harris-style bipod. A 4x scope was also used to ensure consistent sighting.

 

FYI: The "hop twist" of the Tanio Koba IS NOT intended to produce a "rifling" effect on the BB. Rather, it was designed by Tanio Kobayashi, as a sort of air "vortex" wrapper that is supposed to keep the BB away from the barrel. Thus, minimizing or eliminating BB bounce as it traverses the length of the barrel once fired.

 

 

 

SAMPLING

 

 

BEFORE

 

 

 

AFTER

 

[PlasticMag]

What were the grouping diameters before and after? Was this supported or unsupported? Prone? Standing? Kneeling? I like where this is going, thanks for starting this!

[sgtHanzo]

What were the grouping diameters before and after? Was this supported or unsupported? Prone? Standing? Kneeling? I like where this is going, thanks for starting this!

<{POST_SNAPBACK}>

 

AEG was fired while on top of a table supported by a Harris-style bipod. A 4x scope was also used to ensure consistent sighting.

 

I should've measured the targets right after each test. Hope the following helps.

 

Target used "BEFORE barrel install"

 

Target used for "AFTER barrel install"

[Hatman]

Target used for "AFTER barrel install"

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That doesn't look promising, no hits at all there.

[sgtHanzo]

That doesn't look promising, no hits at all there. 

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Didn't you know? Projectile used on that one was some sort of a super-duper secret microwave particle. It's able to vaporize target without visible damage to paper barrier.

[Hatman]

I sooo want one of these barrels now... lol

 

I am actually very interested, just does anyone know how well they will do in an ICS AK74?

[The Saint]

The difference is FPS between a clean and unclean stock barrel is totally irrelevent.

 

Did you clean the Tanio barrel as well?

 

Why didn't you use the same type of target for both tests?

 

Was the hopup re-zeroed after installing the Tanio?

[sgtHanzo]

The difference is FPS between a clean and unclean stock barrel is totally irrelevent.

 

Did you clean the Tanio barrel as well?

 

Why didn't you use the same type of target for both tests?

 

Was the hopup re-zeroed after installing the Tanio?

<{POST_SNAPBACK}>

 

- TK barrel was swabbed once just to make sure there aren't any foreign debris inside the barrel big enough to affect the outcome.

 

- Hop-up generally works only after 75ft. This test was conducted at 45ft. indoors.

 

- All tests were done with zero hop-up.

 

- I ran out of the silhoutte target (only had one). It's the reason why I switched to a round target. In any case, I was more concerned with the "grouping" vs. the kind of target used. Triangulation can always be acquired/re-acquired as long as consistency exists.

 

One observation though. Hop-up does work even with the TK barrel installed. I sighted a target 100ft. away (outdoor) and I could see the "Bernoullie effect" kicking in. Too bad I can't place a target at that distance (village tree).

[Wege]

Uhh.. The TK website states that the TK twist barrel is intended to be used at 1J, and not at higher velocities...

[litefire1546]

Is it just me or does there look like there is no difference in accuracy? You should perform the test again using the same target in both, and use a more accurate set up to test it. Trigger pull can cause a change in aim, causing larger groupings. I would suggest putting the bipod down, and using a vice to hold the stock in place. Aim it and use the vice to keep it exactly in place as you pull the trigger. That will give you much more accurate results. I don't trust that the data in this test are largely affected by human error.

 

BTW, i'm interested to see how this turns out. Also, i'm interested in what happens when hop up is put on. I've heard that bb's spin off target when they get downrange.

[sgtHanzo]

Is it just me or does there look like there is no difference in accuracy? You should perform the test again using the same target in both, and use a more accurate set up to test it. Trigger pull can cause a change in aim, causing larger groupings. I would suggest putting the bipod down, and using a vice to hold the stock in place. Aim it and use the vice to keep it exactly in place as you pull the trigger. That will give you much more accurate results. I don't trust that the data in this test are largely affected by human error.

 

BTW, i'm interested to see how this turns out. Also, i'm interested in what happens when hop up is put on. I've heard that bb's spin off target when they get downrange.

<{POST_SNAPBACK}>

 

Nope. Not just you. Based from what I've seen the performance of the TK barrel, at the FPS specified above, is almost negligible (compared to a stock 509mm).

 

I thought the test should be conducted the way the airsofter would fire the AEG out in the field. It's the reason why I didn't bother using a vise (to hold the AEG tighter). However, at a distance of 45ft-50ft, the result should be consistent enough -- as long as proper trigger control, breathing, sight picture / sight alignment are used. I followed the principles above as best as I could with each BB release.

 

Another observation. 2 of eight rounds, or 1 in 4 tends to hook wide, either to the left or right by about 2" to 3". At a much farther distance (2x or 3x), this performance would classify as "terribly poor."

 

I'll try and get a 6.03 or 6.04 tightbore for comparison. Will post additional data as I get the chance to do additional tests.

 

[litefire1546]

I would still suggest a mechanical way to hold it in place. That will take all human error out of the equation. It doesn't make sense to try and do it the real way because we're just trying to figure out which is more accurate. I don't know how to explain it, it just doesn't make sense to do it that way. Don't take that the wrong way, though. I'm glad that someone is doing this.

[The Saint]

Another observation.  2 of eight rounds, or 1 in 4 tends to hook wide, either to the left or right by about 2" to 3".  At a much farther distance (2x or 3x), this performance would classify as "terribly poor."

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The hooking is indicative of your FPS being too high for the TK barrel to work properly.

 

I'd recommend you clamp the gun down next time. There's no "the way the airsofter would fire the AEG out in the field" when you're measuring spread. You need to eliminate as many other variables as possible, with human handling being at the very top of the list.

[sgtHanzo]

Thanks guys! Once my rifle bench clamp arrives, I'll get another sampling that even the Mythbusters will be proud of.

 

[MattCFII]

Thanks for the tests!

 

Are you going to downgrade your spring to around 1J power (M100 spring) for testing? As litefire1546 and The Saint suggested your power is well over the recommended level since with .20s your gun is probably around 400fps and is probably what is casing the hooking of your shots. Also it's been said that it has to be under 1J with any BB not just under 330fps by using higher weight BBs because the airflow is still too much despite the slower BB.

 

Your test would definitely seem to show that the 1J power limit is real with the barrel (or possibly that the barrel just sucks altogether at any speed). I'm thinking of buying one for a bone stock gun and I'd really like to see test at recommend power or below! With your rifle rest coming it should be a real accurate test.

[Sale]

I would still suggest a mechanical way to hold it in place. That will take all human error out of the equation. It doesn't make sense to try and do it the real way because we're just trying to figure out which is more accurate.

I can't speak for SgtHanzo, but I've shot .22 LR rifles from a table top supported by a random bag I had with me, and put 5 shots into groupings as small as 9 mm from 50 meters. With airsoft guns, the human error factor is proportionally small if the shooter has any skill and is using a bipod and scope.

 

I think it makes perfect sense to try the accuracy in "field conditions". If you can't measure any difference in those conditions, it's safe to say that the difference is small enough not to matter to the majority of airsofters.

 

-Sale

[MattCFII]

I can't speak for SgtHanzo, but I've shot .22 LR rifles from a table top supported by a random bag I had with me, and put 5 shots into groupings as small as 9 mm from 50 meters. With airsoft guns, the human error factor is proportionally small if the shooter has any skill and is using a bipod and scope.

 

I think it makes perfect sense to try the accuracy in "field conditions". If you can't measure any difference in those conditions, it's safe to say that the difference is small enough not to matter to the majority of airsofters.

 

-Sale

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I agree that if you know how to shoot a bipod and scope should be almost as good as a Ransom clamp bench rest for airsoft. I've been shooting guns, bb, pellet, real steel, airsoft, ect. from the age of 10 so I feel confident I could print good groups with a bipod and decent scope. But not everyone out there knows the principals of good marksmanship so getting rid of the human element would be nice but not necessary in all tests.

 

Field test are the true test of any upgrade, but getting a repeatable test to compare apples to apples is important. With as much effect wind has on a airsoft BB it means you would have to practically record the wind for each shot to get a true baseline to see if it's the wind or the barrel (not easy unless you have a weather station). I think controlled testing is the best way to show if there is any differences between the barrels and then take it outside to see if that those small or large lab results actually get you better results in the real world. Without the controlled test you have no way of knowing if it was just the wind that changed between barrel installs causing the differences or even to seem to perform the same when one was really more accurate.

 

However if you take the barrels outside and one shot groups twice as small but they both still have the same effective range, the controlled test are just academic, but you still need the controlled to factor out the variables.

[Tecro]

Nice tests.

 

Other reports have also documented the occasional random BB flying out to the side. Maybe there's a design flaw that makes perfect installation difficult or impossible.

 

I also agree you should try 1 Joule, for best effects if not to contend with the ArniesAirsoft limit. I've heard it said that 1 J is the best, and then the effects become worse as the FPS difference is increased.

 

Overall, I'm no longer impressed by the reports of the barrels. A regular TB gets tight(er) groupings and would noticeably increase the FPS, not decrease it.