airsoft accuracy improvement

[Demon]

Just a quick question, a google search yielded nothing.

Has anyone ever attempted to, in attempt to imitate rifling, had the entire barrel assembly rotate on itself while the airsoft bb to be propelled was constricted in place by a rubber sleeve inside the barrel ? Even simpler, only rotate a very small part of the barrel, the one containing the BB before shooting.

Obviously it would be electric, and then the ''rifling'' of the barrel could be adjusted by changing the RPM of the barrel piece holding the BB in place.

Ever attempted/thought ?

[al-xg]

Rifling tends to induce rotational speeds well in excess of what would be practical with moving parts, when it comes to oblong projectiles anyway.

In airsoft, the BB doesn't need stabilising as such, however, giving it consistent initial starting conditions with help with accuracy. And in this case one might as well give it backspin to use the magnus effet to flatten out the trajectory, hence the use of hop-ups.

The airsoft community often talks about air cushioning and tight bore barrels for accurately sized BBs when accuracy is concerned. This isn't so much of an issue with other projectile launchers.
As far as I understand, from what airsofters say, the pressure at the muzzle when the BB leaves the barrel is quite an important factor. Too much pressure will cause a turbulent muzzle blast, too little pressure will cause the BB to bounce about in the barrel giving an unpredictable trajectory.

[Demon]

You are quite right about the unattainable RPM, for firearms it goes around 250,000 RPM

But then, what about only 1000 RPM ? wouldn't it be sufficient for slower projectiles ? This is to avoid the secondary effects of hop-ups that cause to BB to considerably slow down past a certain distance.

[jackssmirkingrevenge]

For an airsoft BB at 500 fps you'd want around 50,000 rpm, not impossible to achieve.

This doesn't solve much though.

http://msed.bbbastard.com/index.php?opt ... &Itemid=59

Airsoft BBs are so poor in terms of sectional density and muzzle velocity that their ballistic drop and potential for environmental influence is tremendous. For real accuracy you would need a ballistic computer hooked up to a laser rangefinder and weather station.

[wyz2285]

I don´t think a airsoft bb need to spin considering that it has a backspin caused by the hop-up... If it spins wouldn´t the trajectory be like a "S" shape?

[al-xg]

No it would just curve off to one side and drop more or less quickly depending on the direction and intensity of the side wind.

[bobgengeskahn]

http://www.airsoftforum.com/board/Tanio ... 47334.html



These have been around for a while now and have been a very hotly debated topic in the airsoft community, but they have never really caught on since the concensus seems to be that with standard airsoft BBs the twist really doesn't do a whole lot. If we were still using BBs like the Asahi M40 it may yield better results. however the cost of introducing new BBs into the market on a mass scale is not worth reaching out to the very small number of people that actually want accuracy.

http://www.airsoftforum.com/board/lofiv ... 40261.html

[flashskate13]

I'm pretty sure for rifling to work the projectile would have to be longer than it is wide for a stabling factor like a bullet otherwise when the Bb loses fps, accuracy would be all over.

Back spin via hop up system tight bore and remove any movements that my affect accuracy.

Don't think you will ever be able to get much more range and accuracy using a Teflon projectile

But would be nice to go out on the field and hit targets well out of others range

[jackssmirkingrevenge]

I'm pretty sure for rifling to work the projectile would have to be longer than it is wide for a stabling factor like a bullet otherwise when the Bb loses fps, accuracy would be all over.

Actually rifling has been around long before cylindrical bullets were invented.

Does the rifled barrel also have hop- up? If so, penn and teller would say it better than me.

For example: http://hammerheadpaintball.com/index.ph ... &Itemid=14

We found the rifling needed to be done with a precisely correct depth and width of grooves and lands. This was needed to achieve required ball rotation, and the ability for most paints to self clean themselves after paint breaks. (Some paints will not self clean, but many will by flowing broken paint down the valleys of the rifling). We also found the rate of rotation and the velocity was critical to rifling performance. We finalized the rate of ball rotation with the targeted ball velocity of 280 ft/sec. Once the ball rotation exceeded a specific RPM, the ball tended to wobble at the longer distances. At the higher rates of rotation, we believe the shell spins faster than the paint, and the paint then absorbs the energy of the spinning shell. The Hammerhead barrels rotates the paint in a clockwise rotation simultaneously with a “slight” backwards rotation. We are gently rotating the balls in both directions and do not claim nor do we want to spin them. It is a very gentle ball rotation to achieve the accuracy. Hammerheads rifling does in fact rotate the ball in two directions and we found we could significantly improve the ball accuracy and get 20 ft or farther distance with a slightly flatter trajectory than a standard non-rifled barrels. We can only speculate that by rotating the ball, the drag behind the ball was made more uniform, and reduced the overall drag on the ball. Reduced drag and counter-rotation with a slight back-spin combines to make the ball fly slightly father and straighter.

These charlatans are claiming that you can gain accuracy through rifling -and- backspin, which makes no logical sense whatsoever. You can see it in their high speed videos, if a projectile is tumbling end over end then the spin induced by rifling is having no effect at all, if the thing is spinning along more than one axis.

[flashskate13]

i stand corrected just found this on wiki.

In the 1840s and 1850s, many smooth bore muskets had their barrels rifled so that they could fire the new Minié ball. These "rifled muskets" or "rifle muskets" were long enough to serve the function of muskets in close formations of line and square, were as quick to load as the old muskets and as easy to use with a minimum of training. Yet the Minié-type rifled muskets were much more accurate than smooth bore muskets. The loose fitting ball in a smooth bore musket was only accurate to about 50 or 75 yards. Rifled muskets increased the effective range to about 200 or 300 yards, and a rifled musket could often hit a man-sized target up to 500 yards away.[6] This potential accuracy, however, required skills only acquired through training and practice; a rifle-musket in the hands of a raw recruit would not have performed very much better than a smoothbore.

but they did adapt the projectile.

[Southclaw]

I was wondering when someone would bring that up! Rifle muskets were a huge jump in technology! I think, if properly used, are the next step for airsoft guns. The mini ball seems to be a logical projectile to. All these weired shapes seem to complex!