Clear Barrel Experiments

[mcguyver]

Sure, why not a powder coating, or perhaps a thin wax? Something that would be transferable in the event of an impact. It would be a lasting indicator that could be viewed from multiple angles and without the need for high-speed imaging of a fixed position.

[Deadpool]

Originally Posted by mcguyver

Sure, why not a powder coating, or perhaps a thin wax? Something that would be transferable in the event of an impact. It would be a lasting indicator that could be viewed from multiple angles and without the need for high-speed imaging of a fixed position.

I think that any addition to the BB would affect or even negate the effect of the hop-up on the BBs.

multiple slow motion cams would show any impact and effects IMO.

[mcguyver]

Originally Posted by Deadpool

I think that any addition to the BB would affect or even negate the effect of the hop-up on the BBs.

multiple slow motion cams would show any impact and effects IMO.

Most if not all BBs already have a surface treatment. A thin layer of something if chosen and applied correctly won't have much effect.

For the purposes of this proposed experiment, the finely-tuned hopup is irrelevant. This is to answer the age-old question of the BB touching the inner barrel during flight.

[peacekeeper]

Maybe do a twist barrel if possible , that would be interesting.

[Dynamo]

Originally Posted by peacekeeper

Maybe do a twist barrel if possible , that would be interesting.

a clear twist barrel.. really?
i don't think BBB would have the $$$ to shell out to make a rifled acrylic barrel. just a simple smooth bore is going to be expensive enough.

[Blackthorne]

Originally Posted by invisiblehand

Have you considered adding smoke to see the movement of the air? While this isn't directly related to the hopup, it would help to show if the BB is being held off the walls of the barrel by the air cushion?

Interesting angle we had not thought about. Wouldn't do much in the barrel but it might show the turbulence and any associated patters at the muzzle.

Originally Posted by Cpt- Lovegrove

i hope you plan on releasing a video of the tests especialy of the highspeed shots, i would love to see them

We will be release a paper in PDF format and doing a complete video review of all our work, from the build through to any tests we run.

Originally Posted by ThunderCactus

Like I've said before, there's a maximum range and accuracy that can be achieved with a given weight of BB
Once you've topped out the performance capability of the BB, nothing you do to the gun is ever going to make that BB fly further or straighter.

So with any BB your optimal relative velocity is around 320-350fps, any faster and it destabilizes too quickly, any slower and you're just not getting the most out of it.
Once you hammer out barrel, volume, and compression requirements, the only thing left is barrel length. It's just a question of at what point does the BB stabilize itself within the barrel. For GBBRs and pistols, that's about 80mm or so, much more difficult to tweak with GBBRs since longer barrels tend to raise fps, which requires heavier ammo, which in turn raises the muzzle velocity even more.
AEG's tend to stabilize perfectly around the 420mm mark. Any barrel beyond the point of stabilizing is just useless metal. It's allowing more time for the BB to be DE-stabilized by potential fouling in that barrel.
Two VSR-10s built exactly the same internally, one with a 650mm barrel and one with a 420mm barrel, both shooting .3s, or one at 380 and one at 470, or 470 with .36s vs 440 with .3s, doesn't matter what combo we use, the 420mm barrel was never bested by the 650mm in terms of accuracy.
In fact, the 650mm barrel had worse accuracy when using .3s at 470fps

The idea that longer barrels increase accuracy in airsoft was carried over from real steel, but the physics of the two are completely different.

100% agree.

Stalkers work also indicates roughly the same results. We also have three "wide bore" barrels to test as that seems to be the cool new direction as of late.

Originally Posted by Dynamo

a clear twist barrel.. really?
i don't think BBB would have the $$$ to shell out to make a rifled acrylic barrel. just a simple smooth bore is going to be expensive enough.

Indeed. The "barrels" we are using are precision bore Pyrex labglass. Inner bore accurate to .0005 of an inch. We are going to have to properly crown them and see if they will fit into exiting hop ups, so prep time may take as long as a few weeks. Nothing custom made and these were not cheap.

[Ricochet]

I've heard of people having visible marks or scratches on the inside of their barrels. This is not something I've noticed in my gun. My barrel is now five years old, and the inner bore looks like new.

Wide bore barrels is a neat idea, but your now changing basic physical factors. You could provide the ability to have a larger more stable air cushion; but at the same time you need something capable of creating a very large air cushion. Not to mention sustaining it now there is more room for air to escape past the BB.

Your average AEG barrel five years ago came 6.08mm, now they are mostly stock 6.04mm. Systemas come stock with a 6.04mm, and mixed with their hop-up style have the best BB flight I've seen. That's electric, piston, air nozzle.

Here's a question for you physics guys. If you had a barrel that was wide bore out of the hop-up to help stabilize the BB's air cushion, and it slowly bored down the further down the barrel you got. The barrel itself would have a fluted tip, and a large, hard, concave style bucking; to apply an aggressive spin. Let's say the barrel started as a 6.08mm, and reverted down to a 6.03mm by the tip. Now the BB's squeezed path might slow it down, but could you not compensate with a stronger spring; or would the air cushion being forced into a decaying bore, compress and speed up the BB. Or at the very least compensate for the air restriction going into a smaller space?

Stupid question of the day? Or has someone already tried this in the Airsoft world?

[Danke]

Glow BBs?

I know, white against a black background is almost the same.

[Dynamo]

having a barrel taper down could cause any destabilization of the BB to be carried down all the way to the end of the barrel. i'm sure there is some oscillation on the Z axis when the BB is released from the hopup. with a tapering of the bore, it could delay the stabilization or even amplify the oscillation effect.

Originally Posted by Ricochet

I've heard of people having visible marks or scratches on the inside of their barrels. This is not something I've noticed in my gun. My barrel is now five years old, and the inner bore looks like new.

Wide bore barrels is a neat idea, but your now changing basic physical factors. You could provide the ability to have a larger more stable air cushion; but at the same time you need something capable of creating a very large air cushion. Not to mention sustaining it now there is more room for air to escape past the BB.

Your average AEG barrel five years ago came 6.08mm, now they are mostly stock 6.04mm. Systemas come stock with a 6.04mm, and mixed with their hop-up style have the best BB flight I've seen. That's electric, piston, air nozzle.

Here's a question for you physics guys. If you had a barrel that was wide bore out of the hop-up to help stabilize the BB's air cushion, and it slowly bored down the further down the barrel you got. The barrel itself would have a fluted tip, and a large, hard, concave style bucking; to apply an aggressive spin. Let's say the barrel started as a 6.08mm, and reverted down to a 6.03mm by the tip. Now the BB's squeezed path might slow it down, but could you not compensate with a stronger spring; or would the air cushion being forced into a decaying bore, compress and speed up the BB. Or at the very least compensate for the air restriction going into a smaller space?

Stupid question of the day? Or has someone already tried this in the Airsoft world?

regardless of the color of the BB or background, looking through a glass cylinder is going to distort what ever is inside due to refraction.
the effect can be reduced, but not eliminated. even using water or (ideally) mineral oil, there will still be distortion from the internal surface of the barrel. it will make it vary hard to determine the boundary of the glass and the air inside the barrel, so i see it as unlikely that we would be able to tell if the BB is striking the barrel wall or not. this is something BBB has decided to test so i will leave it to them to post their findings. it'll be interesting either way.

Originally Posted by Danke

Glow BBs?

I know, white against a black background is almost the same.

[Danke]

You wont' see the hit but you'll see a sudden change in direction. Glow might trace that better.

[seabass]

Am I the only one curious what they're going to use these barrels after the experiment. Im curious how one would actually perform in a gun.

On a side note. Keep up the good work BBB

[Rommen]

Probably stupid impractical suggestion, but any way to do it electrically? Have a current run through the barrel and coat the bb in an 'electrically responsive coating' (great scientific term I know) that you could use to record where and when it makes contact with the barrel? Somewhat similar in concept to 'touchscreen' coupled with a fencing vest...

[Ricochet]

If your worried about light refraction, then put a very solid black background on the opposite side of the barrel from the camera, put a hood or shroud around the lens, and manipulate your light source according to camera angle, barrel positioning, etc. Have your light source pass by the barrel, and not through it onto a very dark, light absorbing background.

[Metalsynth]

Originally Posted by Ricochet

I've heard of people having visible marks or scratches on the inside of their barrels. This is not something I've noticed in my gun. My barrel is now five years old, and the inner bore looks like new.

Probably due to sand getting in the well of the mags and getting pushed out the same time as the bb or improper cleaning cloth type.

Great idea BBB, looking forward to knowing!

Getting a T asap!

[Blackthorne]

FYI we have had to source cash for this, as the costs to do it correctly are rising fast..

Our crowdsourcing project on Indiegogo

Real Time Airsoft Barrel Dynamics Project