Bullet shaped bb's

[sir naggedalot]

Yeah but like I said earlier in the thread, you have over double the volume in an 8mm bb compared to a 6mm.  That's an awful lot of space to fill with mass, and would suggest you would need really heavy bbs to get long, stable and accurate flight.  I don't think this is workable with sub 350fps guns, maybe an interesting idea for sub 500fps though

 

I think even at 1 joule we could make something better.

 

How about we think of the projectile being like a paper plane,we need to glide the projectile to the target...?//!!!...?...............

 

 

 

My Super Blackhawk does really well with .45g shooting at 2.5J which is right about there in the "interesting idea" range.

 

Youd be surprised how well a stock marui 1911 dealt with 0.9g steel bbs (range only)

To much power for me.......Im usure about MED so would rather have all on same FPS

 

.45g in 8mm is roughly equivalent to 0.20g in 6mm which I would say is the minimum for useful 8mm weights.  I've seen .65g or .64g 8mm bbs somewhere, which interested me.  One more thing about 8mm to make them interesting is that the ratio between volume and surface area on them would make gains from heavioer bbs pay off nicely

How about a lead core with a out'a layer of different materials. I could think of a few ways but lets talk about what we could do in our standard blue peter set ups.

 

lead balls, ball mill, what ever coating you fancy. same ball mill, polish....try... win/fail.....learn.

 

How about graphite,plenty of mesh sizez on the shelf?

 

Are we not talking about non round projectiles on this thread mostly? Bullet shaped is just like a paper dart/plane, right?

 

 

Strangely enough, the most accurate pellets I used to use for precision 10m .177cal air rifle were wadcutters and the same held true for my .22cal and from my understanding, .22LR as well. How fast does the Asahi shoot and relative weights of the rounds?

 Wadcutters at short range use the air cushion affect and like you say prform fantasticly,but at long ranges are ######.

 

Its because of the poor DRAG coefficient. A point has a low BC & DC but not so good CG but you need to get the point or tip DEAD CENTER.

 

Even tiny dimple in place of a point keeps the BC,DC&CG cool but it also LUBES the air flow.....DRAG<LUBE< I GOT'a go to the toilet to have a long hard think about this......

[sir naggedalot]

Well I happen to have an Asahi ..

 

 

 

 

No one likes a boaster!! lol

 

I reckon the tail is more like a streamer as I think there will be very litle interaction with the air flow.If you put a hole in in the center to funnel air to the tail and then directed it out the tail at a angle you could in part spin and make it whistle.

 If  we try to use golden ratios at all times we might even get......... 

 

I do love a few zips wizzes and bangs..

[Lancaster]

I have seen such a product for paintball

 

[spamofthejungle]

If you have a pellet that's got a very thin skirt,say 8mils (0.2mm) and made from poly prop you could use the rifling to create grooves that would hopefully enhance the flight characteristics.Very very little pressure could be used.Lets say the skirt was as thin as a plastic bag but i think tin foil might be better,if only we could combine the two seamlessly.....

 

When I was very young I used to shoot pieces of Sweet (Chewits)from a HW80 Airrifle at a friend.

Surprisingly accurate and they used to engage the rifling very well! 

 

This sounds like a pretty good solution (skirted pellets not ballistic confection) but I can't help but think any skirt weak enough to be deformed enough to engage rifling would be so weak as to make the pellets unuseable, the slightest pressure in the wrong area when loading the specially designed magazine would likely leave a flat side on the skirt. In fact thinking about it simply being in a magazine would deform a projectile with a skirt that weak, shame because a skirted projectile fired down a rifled barrel IS the solution for lateral accuracy, as demonstrated in the world of airrifles.

[sir naggedalot]

This sounds like a pretty good solution (skirted pellets not ballistic confection) but I can't help but think any skirt weak enough to be deformed enough to engage rifling would be so weak as to make the pellets unuseable, the slightest pressure in the wrong area when loading the specially designed magazine would likely leave a flat side on the skirt. In fact thinking about it simply being in a magazine would deform a projectile with a skirt that weak, shame because a skirted projectile fired down a rifled barrel IS the solution for lateral accuracy, as demonstrated in the world of airrifles.

Your right,how about each projectiles nose fits inside the skirt of the other?Its going to make them much more durable when contained and you could fire groups of them and with a bit of luck we might get fairly consitant separation in the air.......

 

Im more into smothbore as if we keep the power sub 1j we are never going to have anough mass as Swerve pointd out to use latral spin imparted with rifling.

short range yes but uber long range no.

 

I think we need to use areodynamics to imprt spin on our projectile long after the interaction between barrel and projectile has ceased.

 

 

For sure 8mils spec skirts is over kill for sure but the thinner the better for flight but your right if they are to fragile the damage is going to affect  consistency adversly.If we have a smothbore we could employ a choke and this might improve things abit?

 

If we are going for long range how about a small projectile that is made from Poly P with a small Iron core then we fire with it with magnets just like a coil or rail gun?

 

 

I like the though of a hollow tube with lets sat hula hoop or cardbord tube with dental floss trailing from it like a flying long range jelly fish..lol

 

To make it simples for some multicored bb players out there,,,,,we need a projectile thats going to incrase in stability at lower speeds.So it needs to be a self stabilizing shape that becomes more stable at range.

 

I reckon we copy these but ad dental floss for now. Flying tampax anyone?

 

http://upload.wikimedia.org/wikipedia/en/f/f0/Plumbata_shotgun_slugs.JPG

[renegadecow]

Stick the flimsy finned projectile in a case which would then eject. You get a pretty accurate, low/mid energy projectile plus fancy case ejection to pelt your mate's face with.

[sir naggedalot]

Stick the flimsy finned projectile in a case which would then eject. You get a pretty accurate, low/mid energy projectile plus fancy case ejection to pelt your mate's face with.

LOL , I seam to remember playing Airsoft with these 2...

 

Even better if we could discard the cases, I hate the having to collect them aspect....

 

I think a paperplane/dart/flechette projectile with a streamer/long tail trailing from the back end would give us great consitant long range shots while staying under 1jand useing  a smoth bore barrel

 

Very poor on gusting days but for those still times...???

[Jibbity]

This was mentioned in on the first page of this thread already, but at normal field velocity limits the extended range and flat flight we get from hop up > then the minor gain in consistency that might come from a rifled barrel/ projectile. Go play a match with your hop turned completely off (and bucking mound removed) and you will see what I am talking about. At ~1 joule, with a level aim, your bbs would hit the ground in 40 to 50 ft in my experience.

[sir naggedalot]

This was mentioned in on the first page of this thread already, but at normal field velocity limits the extended range and flat flight we get from hop up > then the minor gain in consistency that might come from a rifled barrel/ projectile. Go play a match with your hop turned completely off (and bucking mound removed) and you will see what I am talking about. At ~1 joule, with a level aim, your bbs would hit the ground in 40 to 50 ft in my experience.

Your right... spherical projectiles are close to their limits. 

If we remember that the thread is about non spherical projectiles and if fired from a smooth bore then we have to move to some sort of dart I believe just as the military have done after Millions of pounds of R&D.

 

Me thinks that a tear like shape with a long piece of dental floss trailing behind with a minute set of fins would self stabilize very well.Better still two tear drops entwined around each other!lol

 

All these would require loads of  windage and elevation  adjustments but clicking those turrets about is half the fun and who wants to make it to easy for snipers anyways...

Not me, I love nothing more then hunting a camper...

 

As with most shooting,its the consistency thats most important is it not? 

[Jibbity]

Your right... spherical projectiles are close to their limits. 

If we remember that the thread is about non spherical projectiles and if fired from a smooth bore then we have to move to some sort of dart I believe just as the military have done after Millions of pounds of R&D.

The point I was making is that any projectile without lift (hop up) will follow the same trajectory at the same velocity. Gravity is constant, no escaping that. You either need lift of some variety, or a lot more velocity.

[sir naggedalot]

The point I was making is that any projectile without lift (hop up) will follow the same trajectory at the same velocity. Gravity is constant, no escaping that. You either need lift of some variety, or a lot more velocity.

With the use of a very thin/light projectile we would see a great increase in velocity and if we keep the BC&DC low this might give us the sub 1joule range increase?

 

Its funny how some things have a long range just because they are lobed at such a steep angle.

 

When  was very young we used to make a dart out of a piece of small garden cane and with a notch and a bit of string we used to be able to lob them  hundreds of yards,funny thing was the further they flew the more stable they got!

 

To get a good throw,Ie:long range just like throwing the javelin it was key that you got the right launch angle.... 

[Jibbity]

Its funny how some things have a long range just because they are lobed at such a steep angle.

Exactly the point that I was making is that a mild increase in accuracy is not worth using grenade launcher sights within 100ft of my target. 

 

In my mind that is...

[sir naggedalot]

Hopefully we would only endup with grenade launcher sights if the velocity was very low.

 

If we start with a high velocity but end up with a stable flight pattern at the long range low velocities we could end up with a massive increase in accuracy.Not mild at all hopfully !

 

 

Look at how those skirted paint balls preformed, massive increase in range from what I could see with very little fps or mass increase and all from a smoth bore no? it l;oked like a great bit of sniping for paint balling!    

 

None of that deviation you get at long range with a paint balls and bb's  as the back spin fades as I am hoping that spin will be imparted from start to finish via the aerodynamics of the projectile 

 

talking off deviation im off to feed the wife...!!!! lol

 

if only i had a top draw £D printer we could be testing these hypothes now!

[Jibbity]

Hopefully we would only endup with grenade launcher sights if the velocity was very low.

Seriously, go shoot a few rounds with no hop. You will see what I am getting at.

[Swerve]

bear in mind that we would be firing at human flesh, so the profile of any round cannot have corners, edges or points, and not just on the leading profile, as you need to take possible deflection/tumbling into account.

 

Any grooves on the round would need to be recessed, rather than proud

[sir naggedalot]

bear in mind that we would be firing at human flesh, so the profile of any round cannot have corners, edges or points, and not just on the leading profile, as you need to take possible deflection/tumbling into account.

 

Any grooves on the round would need to be recessed, rather than proud

I Second that,if your went for a contemporary Flechette the we would need to keep the all radius's similar to a 6mm bb but im thinking it might be better to make them from a dense rubber.If we could use combinations of materials that might help? A rubber teardrop with a few fins twisted around it made from sothing like dental floss might work..  

 

I like the idea of a non Newtonian fluid that goes solid as we accelerate it, then forms a tear drop in the air at the perfect Fibonacci golden ratio until the projectile hits, at this point it sticks like a bogey so i can prove i hit you at 250mlol

 

the flying snot shot

 

Funny how when you spit from a tall building it always falls strait till surface tension is overcome....

[sir naggedalot]

Seriously, go shoot a few rounds with no hop. You will see what I am getting at.

I know what your getting at without flexing a muscle....

[Swerve]

I've just knocked this up in paint.  It is a tic-tac shaped 6mm diameter cylinder that is essentially two bbs joined together with the voids between them filled (conceptually, I know construction would be different)

 

Spiral grooves are then added along the main cylinder body, probably about 0.5mm depth/width

 

My questions are:

 

a. What would be the flight characteristics of this hybrid bb round if it was fired through a smooth bore TM VSR with zero hop applied?

b. Would the grooves provide a 'self rifling' effect, causing the round to spin in flight along its longitudonal axis?

c. If self rifling is occuring, would this help to provide stable flight?

d. Would making the hybrid round heavier at the front be of any benefit?

  

Info to take into account:

1. The test gun in question is firing normal 0.20g bbs at 500fps

2. The weight of the hybrid round is 0.40g (based on two 0.12g bbs with similar mas material filling the void).

3. We are assuming that each round will be absolutely idential in every respect.

4. We are assuming that the VSR rifle will shoot with consistent power every time.

 

My own thoughts are that the flight would still follow a parabola/falling curve like an un-hopped bb, but the flight would be stable and consistent from shot to shot.  With that being the case, then a scope with ready made offsets on the vertical plane could be developed to take the parabola into account, allowing you to 'lob' your shots. 

 

See pic below

 

 

tic tac mints for reference:

[sir naggedalot]

I think you already know the answers but I would say A;lets hope so  B:yes  C:yes

 

I think your design is great but if we taper the tail and have a long thin streamer trailing from it that would hopfully make it more stable the longer flight( i know there is a word for this phenomena) just like arrow as its going to improve the BC&CG

 

Its going to have a parabola trajectory but its easy to allow as you said for that. 

 

I like the idea of confectionery ammo as MY Favorite target after Airsofters is confectionery.

[Swerve]

It's a compromise design really, one that would only need the feed mechanism on a gun changed (mag & strike chamber) whilst also staying safe with no part of the profile any worse than a normal sherical bb.

 

This is a sort of response to the OP question, rather than a thought experiment in projectile perfection

[Swerve]

More thoughts on the above

 

Scopes: What could be done with scopes for lobbed shots.

 

Using the same rifle as in my post above and the theoretical cylinder bb, lets say it will hit upper centre mass on a body 70 metres away with a certain amount of elevation.

 

A theoretical pair of scope mounts could be employed in order to 'zero in' the centre of the reticule at this 70m distance:

 

The front mount has a pivot.

The rear mount has an up/down graduated adjuster

 

When this is set, then the upper graduations would then correspond to shorter distances, when aiming to hit upper centre mass on a normal human body.  You would naturally lower your rifle elevation in order to bring the upper graduations of the reticule onto target, thus lowering the flight of your bb

 

Fine tuning can be done using the normal scope turrets for windage and elevation

 

I have just used 70m as an example, and worked it back to 30m as that is close to or at common 500fps site MED rules

 

Again, excuse the pic, just quickly spazzed up on paint

[abbadon101]

The effect of the lanes cut into the "tictac" will impart SOME spin on it but not much as even if you were shooting at 500 on .2's you wouldn't be getting any higher than that (weight of the projectile being quite high) and so the effect of the spin wouldn't be very pronounced.

 

Even air rifles are dealing with muzzle velocities FAR in excess of airsoft guns. For example a 5 foot-pound air rifle is shooting a projectile of just under a gram at ~350 FPS.

 

That equates to 850 FPS on a .2g projectile. 

[Swerve]

ah but we are also looking at relatively short distances here

 

BUT I also realise that it's a double edged sword - a rifled cylinder/bb would allow it to be initially more stable, but would then also produce more drag when out of the barrel, also, how much of the energy initially supplied to the round be 'spent' and getting it spinning.  There's only a set amount of energy available that can be spent on getting the round to target after al

[abbadon101]

A .177 with sub 12ftlbs only have about 35 meters "range". They aren't "effective" after that out of a range environment. 

[sir naggedalot]

I like this alot..   http://www.deben.com/chairgun-pro.html. Allows for alot of data input including shimming of scopes....