Bullet shaped bb's

[Inq Eisenhorn]

OK, so I'm appealing to the scientifically minded members of the forum, of course, anyone is welcome to comment

 

So I've been thinking about the key attributes an air softer should seek from their guns, one attribute should surely be range, perhaps the other, accuracy.

 

Focusing on range, it occurs to me that one the limiting factors with regards to range is the fact we're firing spheres. Given how much research has been done to dictate the shape of a bullet, surely, in order to maximise the range a 'bb' could travel, taking on the shape of a bullet would be one solution.

 

This is where my knowledge (if that) stops. Supposing the material, weight were kept the same as today's bb's, would a bullet shape really increase the range at which an airsoft gun could be effective? Would the revised shape cause a bb to be more dangerous at point of contact?

 

Of course, if anyone were to take this into production some consideration would have to be given to inner barrel rifling, and magazine design would be another big consideration.

 

If this 'simple' change was within the law, and more importantly, safe for users, I can imagine something like this being attractive for serious milsim or, the mythical realms of law enforcement and military training.

 

Anyway, over to the experts.

 

P.S. before anyone says it, I did a search....and found nothing.

[hwagan]

OK, so I'm appealing to the scientifically minded members of the forum, of course, anyone is welcome to comment

 

So I've been thinking about the key attributes an air softer should seek from their guns, one attribute should surely be range, perhaps the other, accuracy.

 

Focusing on range, it occurs to me that one the limiting factors with regards to range is the fact we're firing spheres. Given how much research has been done to dictate the shape of a bullet, surely, in order to maximise the range a 'bb' could travel, taking on the shape of a bullet would be one solution.

 

This is where my knowledge (if that) stops. Supposing the material, weight were kept the same as today's bb's, would a bullet shape really increase the range at which an airsoft gun could be effective? Would the revised shape cause a bb to be more dangerous at point of contact?

 

Of course, if anyone were to take this into production some consideration would have to be given to inner barrel rifling, and magazine design would be another big consideration.

 

If this 'simple' change was within the law, and more importantly, safe for users, I can imagine something like this being attractive for serious milsim or, the mythical realms of law enforcement and military training.

 

Anyway, over to the experts.

 

P.S. before anyone says it, I did a search....and found nothing.

 

 

It's been discussed before in a fair amount of detail, but I can't find the thread either... If I recall correctly, the gist was that;

 

A bullet shaped projectile would fly better, but only assuming it had the benefit of rifling. This would obviously mean the round would need to grip the rifling, which would therefore mean the gun would need to have a higher energy behind it to maintain a given muzzle velocity, putting a lot more stress on the gun itself. 

 

Asahi did it before on their Remington M700 with 'Blade bullets' - These were 6mm projectiles shaped like tiny nerf balls; http://img.photobucket.com/albums/v479/treefrog361/Ammo.jpg - Whilst these were far more accurate, they had to be loaded into shells to be fired, and I believe the Asahi guns that fired them were banned in Japan due to their insane levels of realism (Don't quote me on this, but I seem to remember it was something nuts like swapping the bolt and the barrel would create a real firearm).

 

Essentially it's impractical - With rifled projectiles you'd need a lot more energy behind it to cause the projectile to grip the rifling; That, and you'd need to re-design all new magazines and feeding mechanisms for any gun using them, same as the Asahi blade rounds.

 

 

So there are more accurate projectiles than BB's, but none of them are really practical or suitable for shooting at each other

[ED-SKaR]

So you're going to use non hopped design at 1-1.5j?

 

So, nice and accurate but you'll be outranged by the most pathetic of pistols that do have hop.

[FTZ-WildeCard]

There is perhaps a legal issue (in the UK at least) around launching projectiles from rifled barrels - it has come up when talking about TAG grenades and launchers, would probably apply here as well.

 

That said - would be an interesting concept for sure.

[spamofthejungle]

If it's legal to fire an air rifle pellet from a rifled barrel in this country would it not also be legal to fire a lighter airsoft projectile at lower velocity from a rifled barrel? I thought the issue with the TAG grenades was the weight of them and muzzle energy required to launch them?

Could it be possible to design the projectile to acheive gyroscopically stabilised flight without the need for rifling? Thus not requiring extra energy to push it through a tight rifled barrel? I'm thinking along the lines of Nerf footballs which spin in flight due to the design of their fins.

I think due to the cost of manufacturing the ammunition and magazines this would be impractical to apply to an AEG designed to fire finned projectiles, but for sniper rifles with a much lower ammo capacity that's typically going to get through far less rounds per skirmish and only need one or two extra mags to be useable, this could be excellent.

[volante]

There was 'blade bullet' made by Asahi Firearms which has small wings on it.  

 

We don't need rifled barrel. 

[kenxin]

I thought about this when I learned of rifled slugs for shotguns (where the rifling is in the slug and the shotgun is smoothbore)....I do not know the amount of energy required to stabilize such projectiles thou.

 

I also didn't know about the asahi m700 blade bullets, so thanks for that bit of knowledge.

[spamofthejungle]

Another issue may be the trajectory of the projectile, it's likely to be more curved than that of a BB with Hop-Up. As a BB rotates it creates an area of low pressure above it essentially 'sucking' it upwards in a similar way to the wing of an aircraft. Without this effect I think range might suffer even though the accuracy was increased, or at least Airsoft snipers would need to learn to account for bullet drop much better at varying ranges.

[Im going space]

yes air rifles with rifles barrels may be legal, but it is illegal to fire them at people, thus redundant. i do have some plastic .177 bullet shaped projectiles that fire well out of a 400fps smoothbore CO2 pistol. how well this would scale up however i do no know.

[Mrfoss]

Like ED scar and some others have mentioned the bullet shaped projectile would lose altitude and you whould need to aimed them at an angle and estimate a balistic trajectory to hit your intended target. If you aim as you do with your normal AEG the range whould be terrible. So basicly:

 

spherical BB with hopup is a far better solution then buller shaped BB for airsoft regardless of local law.

[Inari]

Bullet shaped = good at high power

 

Sphere + Hop = good at low power

 

Since airsoft is a low-powered game, where we don't maim or kill each other, the spherical BB will win out every time

[sir naggedalot]

Seeing as dimples improve the flight characteristics of a golf balls I believe a lot more could be achieved by dimpling the ammo.

 

As mentioned before the low pressure caused by backspin is what gives the flat and long flight we are looking for.

 I believe the mass of a plastic bullet ( non-spherical projectiles) would be to low to be stablized  with latral spinning, mass makes the bullet's length axis resistant to the destabilizing overturning torque of the CP being in front of the CG and plastic has very little

[ollie_ty]

Airsoft-Mechanics has some great info about this.

[Baddbaz]

Correct me if I am wrong but airrifles are allowed rifled barrels because they come under the firearms statute laws whereas Airsoft guns are low powered air weopons . Classifed as rifs / ifs Or something similar to that .

[shinigami49]

Like Ollie_ty said there's a pretty extensive thread about this over on airsoft mechanics, link below.

http://forums.airsoftmechanics.com/index.php?topic=5851.0

[DWZippy]

Pretty sure they already made these, years back - well, tear shaped BB's.

 

I'm told they could be converted easily to fire real bullets, so Japan got a bit annoyed and banned them. 

[PureSilver]

Clearing up the Asahi system rumours (again):

1. Yes, Asahi made some guns (at least two variants, I think, of Remington-700-based firearms, one of which was the famous Asahi M40) that used aspherical rounds. They didn't use hop-up (they were fin-stabilised) and as far as I know they also had rifled barrels.
2. Since (admittedly this was back in the day) the Asahi M40 was reputed to be the most accurate airsoft rifle ever made the system seemed to work for them.
3. Because of the weird shape of the rounds (imagine a sherbet lollipop with fins on the stick) the easiest and most realistic way for Asahi to get them to feed was by fitting them into a self-contained cartridge system (similar to BACS).
4. It was for this reason that they were banned in Japan, because the gun was firing-pin fired, barrelled in 6mm, which is near-as-makes-no-difference .22, and chambered in a shell with realistic external dimensions. What this added up to was some imbecile demonstrating that with the correct shell adaptor (which were and are readily available in the States for people that want to shoot dirt cheap rimfire .22 out of expensive .223 rifles) the gun could quite happily fire .22LR rounds. Japanese authorities were less than impressed by that and all extant copies (except those of purchasers too lazy to register their warranties and who had paid in cash) were confiscated and destroyed.
5. A similar system (BACS) was also banned in the UK - in fact, BACS guns are some of the most illegal guns out there. Even if you legitimately bought one prior to the ban, and post-ban had it added to your FAC, it can never be transferred from it and must be destroyed when you give up your FAC or die.

On axial-spin-stabilised projectiles in general:

1. Backspin (applied by hop-up systems) causes the BB to resist the pull of gravity via the Magnus effect, keeping it in the air for longer than a normal parabolic arc. This keeps the BB in the air in the vertical plane, increasing range, but does nothing to improve accuracy.
2. Axial spin (applied by rifled barrels) causes the projectile to resist crosswinds and the like, improving accuracy in the horizontal plane but does nothing to increase range except guarantee the bullet presents its most streamlined profile rather than tumbling through the air. Thus the projectile still accelerates towards the ground exactly as if you had simply dropped it out of the end of the barrel.

If one was to do the sums - and I can't be bothered - you would see that a bullet travelling above the speed of sound travels a lot further in the time it takes to fall to the ground (say a half-second or so from a rifle muzzle at 1.5m off the ground) than a BB moving at 328fps, which is why airsoft employs backspin to delay the BB's fall to earth - to give it a chance to travel further. However, that's not to say that a 0.2-0.4g projectile can't be made to perform better out of a rifled gun; after all, you can buy airgun pellets in the 4-6gr range which corresponds exactly to the 0.2-0.4g range commonly used for BBs; even at lower power these can be exceptionally accurate compared to a backspun spherical projectile like a BB.

 

The reason we aren't all shooting such weapons is pretty simple - cost. As Asahi demonstrated, these aspherical rounds were far more complicated than ordinary spheres, and very intolerant of manufacturing inaccuracies. Asahi's ones were impossible to stack and very difficult to load, hence the need to put them in individual cases. That's OK if you're a sniper shooting ten rounds a game and picking up his brass, but if you're a woodsball player shooting 2,000rds a day? Not practical. Then there's the barrels themselves - their performance is totally dependent upon the consistency of the energy applied to the round, so the twist of the barrel is dependent upon the desired muzzle velocity (a loose example of this would be Tanio Koba's 'twist' barrels, happiest at 1J, though it's not a good example because the rifling doesn't actually interface with the BB directly), and as a result the barrel will only 'work' within a very narrow range of velocities. Fine if you live in Japan and only shoot below 1J; pretty if you live elsewhere and need to find a manufacturer who will sell you a barrel to work at your desired velocity in the correct length. Existing smoothbores are dirt cheap to produce and very forgiving of defects; real rifled barrels are much, much more expensive and much less benign.

 

Wolfgeorge, who owns an Asahi M40, some shells, and some of its (rare, and of course, discontinued) ammunition, really should give us a range report...

[blobface]

I'm not so interested at bullet shaped BBs but golf ball like dimpled BBs... which is a proven concept that it flies much more efficiently, this concept's been adapted by.. golf balls... paintballs... and thanks to mythbusters.. cars.

 

http://www.youtube.com/watch?feature=player_detailpage&v=LKxEkT2H8pI#t=282s

 

I'm sure people would appreciate it when made for heavy weight sniper ammo, theorically it should be able to travel further with the same amount of energy put into it, whether the dimple will badly interact with the hop is anybody's guess... 

 

sorry for hijacking.. but it's kinda relevant... 

[Horsem4n]

can this be the last time we talk about bullet or football shaped BBs? can someone make a pinned topic about it so these aren't constantly made every 13 months?

 

PS, dimpled BBs have also been talked about in depth. one manufacturer even went so far as to attempt making them, but it just cant be done. for the correct amount of dimpling, the dimples would have to be very small. the BBs just couldn't be produced.

[yee245]

I'm not so interested at bullet shaped BBs but golf ball like dimpled BBs... which is a proven concept that it flies much more efficiently, this concept's been adapted by.. golf balls... paintballs... and thanks to mythbusters.. cars.

 

If you're not already aware of them, go look up what limited information there is on the Bioval Dimplex, which is basically what you're thinking of, except never actually released...

[blobface]

can someone make a pinned topic about it so these aren't constantly made every 13 months?

 

Man you must be at least 200 years old to feel that something which re-occurs once every 13 months to be annoyingly frequent... 

[Yuri]

If you're not already aware of them, go look up what limited information there is on the Bioval Dimplex, which is basically what you're thinking of, except never actually released...

 

Yeah, Bioval (who do or did make regular BBs) had promo pictures and everything, but it turned out to be vaporware. This was pretty long ago, eight years maybe?

[Horsem4n]

the problem with topics like this is that they repeat, over and over, with the same thing. they are never any different, the same information gets posted over and over again.

[Inq Eisenhorn]

the problem with topics like this is that they repeat, over and over, with the same thing. they are never any different, the same information gets posted over and over again.

 

Well, blame the search engine, as I have said, I did the search and found nothing. I'm not saying the threads aren't there, but it really depends on the titles that are used.

[sir naggedalot]

I have seen threads on other sites but not on this one mentioning Dimples,while they have bee tried in the past things move on.

 

I long for time when will have 3d printer that print all our Skirmishing the night before we need it.